Case studies—learn from these mistakes

Take a lesson from these unfortunate, true stories about job site mistakes. Expand the “Don’t do what they did!” boxes to see relevant safety information, so you can prevent similar tragedies.

case studies man in hurry 400x525 1

A man in a hurry

A Missouri contractor who called before digging hit a 6-inch high-pressure gas line in an industrial park. He was told the gas company would be locating a line at the site, but he began digging the day before the date set for marking. The line was capped within two hours of the accident, and fortunately there were no injuries or damage. (Source: Underground Focus magazine)

Always call 811 well in advance of digging.
Call 811 before you dig, blast, bore, trench, drill, grade or excavate in any way. They will arrange for marking of underground power lines and other utilities so you can keep your distance. White-line your proposed excavation route, so locators can more easily mark the affected utilities.

Never rely solely on your utility maps.
Utility maps are not updated often, and the markings may be off. The one-call center has the most current, most accurate information about buried utilities.

Know what's below. 811 before you dig.Call 811 well ahead of digging, so underground utilities can be marked and you can work safely.

Worker with jackhammer

Shocking fact:
Not all utilities are members of 811. You are responsible for notifying non-member utilities.

case studies underground lines2

Underground lines can surprise you

A 20-year-old plumber’s apprentice began to jackhammer some concrete, not knowing that a power line lay just beneath him. The jackhammer bit into the line and thousands of volts of electricity surged through his body. The current exploded out the back of his head and shoulder and through his foot, taking two toes with it and burning away part of both knee joints. He spent several months in the hospital healing from burns and it took him two years to learn to walk again. Despite his injuries, the young man went on to become an Olympic kayaker and competed at the 2000 games in Sydney, Australia, where he was the flag bearer for the U.S. team. (Source: Cliff Meidl)

Always call 811 well in advance of digging.
Call 811 before you dig, blast, bore, trench, drill, grade or excavate in any way. They will arrange for marking of underground power lines and other utilities so you can keep your distance. White-line your proposed excavation route, so locators can more easily mark the affected utilities.

Never rely solely on your utility maps.
Utility maps are not updated often, and the markings may be off. The one-call center has the most current, most accurate information about buried utilities.

Know what's below. 811 before you dig.Call 811 well ahead of digging, so underground utilities can be marked and you can work safely.

Worker with jackhammer

Shocking fact:
Not all utilities are members of 811. You are responsible for notifying non-member utilities.

case studiens double duty v3

Don’t do double duty as spotter and ground rigger

A crane operator was putting up steel beams for a building annex. His brother-in-law was acting as both spotter and ground rigger, attaching the steel beams to the crane. A high-voltage line ran by the job site. The crane operator reminded his relative to help him keep the crane at least 15 feet* from the line, but something went wrong. The brother-in-law signaled the crane to get too close to the line, and when he grabbed the crane cable to attach a steel beam, he was electrocuted. (Source: Worker Beware video)
*Today, per OSHA regulations, this clearance would be at least 20 feet.

When you guide a load, you are at risk of electric shock.
If the crane or other piece of equipment you are guiding hits an overhead power line, electricity can travel down the tag line that you are holding and through you. In the event of power line contact, workers on the ground are in the greatest danger of shock.

Don’t try to guide a load and spot at the same time.
Assign a spotter whose only job is to make sure the equipment stays clear of power lines. Spotting effectively needs someone’s full attention.

When you guide a load, have a spotter who can alert you if equipment gets too close to power lines. Your life could depend on it.

Worker guiding load

Shocking fact:
A worker was electrocuted while pulling a wire rope attached to a crane cable. The cab of the crane was positioned about 11 feet from a 7.2 kV power line. The crane operator swung the crane boom and cable toward the victim, and the momentum of the swinging crane apparently caused the crane cable to contact the power line.

case studies watch irrigation pipes v2

Watch those irrigation pipes

A 19-year-old apprentice nurseryman was fatally electrocuted while installing a sprinkler irrigation system. He apparently lifted up a long aluminum pipe, and it contacted an overhead power line 28 feet off the ground. The young man received a shock of 22 kV of electricity. He was knocked to the ground and dropped the pipe. He told his coworkers that he was okay, and got up. However, he then staggered for about 25 feet before he collapsed and died. (Source: Victoria Department of Labour, Occupational Health, and Safety Division)

Steer clear of power lines:

  • Ask your utility company to identify power lines in the area and familiarize yourself with their location.
  • Store wheeled irrigation equipment at least 100 feet from power lines, and keep irrigation pipe at least 20 feet away from all overhead power lines. (Higher voltages require larger clearances.)
  • When installing aboveground irrigation systems, keep pipes horizontal so you don’t lift them into lines by mistake.

Adjust spray to avoid shock hazards.
Sprinkler streams from an irrigation system should break into droplets as opposed to flowing in a single unbroken stream. An unbroken stream of water that contacts a power line can conduct electricity and cause a dangerous shock.

Keep irrigation pipe at least 20 feet away from all overhead power lines. Higher voltages require greater clearances.

Irrigation system

Shocking fact:
Many farms have no power lines running over their fields, but certainly have them present in equipment and grain storage areas. When transporting irrigation equipment, be sure the paths between the storage areas and the fields are safe routes.

case studies a spotter saved

A spotter could have saved them

A truck driver and his employer (the company president) were electrocuted when the boom of a truck-mounted crane contacted a 7.2 kV power line. The driver was operating the crane by a handheld remote-control unit and was unloading a cube of concrete blocks. While the driver, the company president and a masonry contractor were focused on watching the blocks, the tip of the crane boom contacted the overhead power line and completed a path to ground through the truck, the remote control unit and the driver. The company president tried to help and apparently contacted the truck, completing a path to ground through his body. He died on the scene. The truck driver later died at the hospital. (Source: National Institute of Occupational Safety and Health)

For equipment operators, visibility is limited.
When you operate hoisting equipment, it is often hard to judge the distance from your equipment to power lines overhead. Certain weather conditions and bright or dim lighting can make it even harder to see.

A spotter helps you stay clear of overhead lines.
Someone on the ground has a much better view of the power lines near you. You should work with a dedicated spotter on the ground whose only job is to watch your equipment and make sure you stay a safe distance from overhead lines and other hazards.

Crane and derrick operators:
Maintain continuous contact with a dedicated spotter to comply with electric line clearance requirements. Make sure your spotter is not doing double duty by spotting and guiding a load at the same time.

A dedicated spotter on the ground should be stationed to watch that your equipment stays away from power lines.

Shocking fact:
Construction workers in Manhattan don’t have to worry about contacting overhead power lines. A court order decades ago required that all power lines must be underground for safety reasons. Since then, many other large downtown areas have followed suit.

case studies dont become victim

Don’t become a victim by helping

A 46-year-old man was electrocuted on a tree-trimming job. The accident occurred as a hydraulic bucket came into contact with a 7.62 kV line. A worker noticed that a tire on the bucket truck was burning, attempted to move the truck, and was shocked. He was not able to let go of the door handle. The 46-year-old was electrocuted when he tried to free the worker from the door handle. (Source: St. Joseph News-Press)

Stay away.
Stay clear of any person or any object that is in contact with a power line. Call 911 and the electric company immediately. Don’t try to rescue the victim. Stay away until rescue workers assure you the power has been turned off.

Protect yourself.
If you touch someone who is in contact with electricity, you could be shocked too. You can also be shocked if you touch the vehicle or equipment that person is in, or the tool they are holding. Again, the best thing to do is to stay far away and call for help.

Immediately call 911 and the electric company if someone accidentally contacts a power line. Don’t try to help the victim until you’re sure the power is off.

Power line contact victim

Shocking fact:
It’s human nature to want to help someone who is being hurt. But when a power line is involved, you can’t help without endangering yourself. Do not try to use nonconductive ropes or tools to push an electrical contact victim clear of a power line—power line voltages can be strong enough to travel through nonconductive objects.

case studies always call 911 1

Always call 911 if gas is leaking

A Minnesota contractor severed a buried natural gas pipeline with digging equipment. He reported the leak to his supervisor, but did not call 911 or the local utility company. Within 40 minutes, gas migrated into a nearby building and exploded, killing four people, injuring eleven and destroying six buildings. (Source: National Transportation Safety Board)

There’s no such thing as minor damage to utilities.
What looks like a small nick in a gas, sewer, electricity or water line can result in a major health and fire hazard to the surrounding neighborhood. And damaged phone lines or fiber optic cables can disrupt 911 emergency service.

Never bury a damaged utility.
Trying to cover up an accident can be dangerous, and can lead to costly damages or criminal charges against you and your company. Take the following steps instead.


In case of electrical contact:

  • If you can do so safely, move the equipment away from the line.
  • Stay on the equipment until utility workers say it is safe to get off.
  • Warn others away. Anyone who touches the equipment or even the ground nearby may be injured or killed.
  • Have someone call 911 and the local electric utility immediately.

If fire or other danger forces you off, fold your hands across your chest and jump clear, keeping both feet together and without touching the ground and the equipment at the same time. Shuffle away, keeping your feet close together and on the ground. Or, hop away on two feet, keeping both feet together.


In case of gas pipeline contact:

  • Warn others and evacuate the area immediately.
  • Do not use matches, cell phones, radios or lighters. Even a tiny spark, such as starting a vehicle, could ignite the gas.
  • Leave the excavation open. Do not operate pipeline valves or bury the line.
  • Call 911 and the local gas utility immediately.
  • Stay away from the area until safety officials say it is safe to return.

If you damage a gas pipeline that results in a release or suspect a gas leak, immediately call 911 and the local natural gas utility.

In the event of any type of utility contact, take appropriate safety steps and notify your supervisor and the utility immediately.

Learn the warning signs of a gas pipeline leak.

  • A distinctive, sulfur-like odor
  • A hissing or roaring sound
  • Dirt spraying or blowing into the air
  • Continual bubbling in water
  • Grass/plants dead or dying for no apparent reason
case studies if you smell gas

If you smell gas, get out fast

A 39-year-old Canadian woman refused to leave her home despite a gas line rupture, and was killed when the gas exploded. The woman’s husband had hit a buried natural gas line while digging footings for a room addition. He went into the house and warned his wife of the gas leak, but she assured him she was safe. The man went back outside to wait for repair technicians to arrive. The explosion knocked the man down, and he was dragged away from the flames by a friend. The woman died in the fire. (Source: Alberta.com news report)

There’s no such thing as minor damage to utilities.
What looks like a small nick in a gas, sewer, electricity or water line can result in a major health and fire hazard to the surrounding neighborhood. And damaged phone lines or fiber optic cables can disrupt 911 emergency service.

Never bury a damaged utility.
Trying to cover up an accident can be dangerous, and can lead to costly damages or criminal charges against you and your company. Take the following steps instead.


In case of electrical contact:

  • If you can do so safely, move the equipment away from the line.
  • Stay on the equipment until utility workers say it is safe to get off.
  • Warn others away. Anyone who touches the equipment or even the ground nearby may be injured or killed.
  • Have someone call 911 and the local electric utility immediately.

If fire or other danger forces you off, fold your hands across your chest and jump clear, keeping both feet together and without touching the ground and the equipment at the same time. Shuffle away, keeping your feet close together and on the ground. Or, hop away on two feet, keeping both feet together.


In case of gas pipeline contact:

  • Warn others and evacuate the area immediately.
  • Do not use matches, cell phones, radios or lighters. Even a tiny spark, such as starting a vehicle, could ignite the gas.
  • Leave the excavation open. Do not operate pipeline valves or bury the line.
  • Call 911 and the local gas utility immediately.
  • Stay away from the area until safety officials say it is safe to return.

If you damage a gas pipeline that results in a release or suspect a gas leak, immediately call 911 and the local natural gas utility.

In the event of any type of utility contact, take appropriate safety steps and notify your supervisor and the utility immediately.

Learn the warning signs of a gas pipeline leak.

  • A distinctive, sulfur-like odor
  • A hissing or roaring sound
  • Dirt spraying or blowing into the air
  • Continual bubbling in water
  • Grass/plants dead or dying for no apparent reason