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

A man in a hurry

A Missouri contractor who called 811 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)

Notify 811 before you dig or move earth in any way. This free service will arrange for {Utility Name} and other 811 member utilities to locate and mark their underground lines so you can dig a safe distance away from them.

Dial 811 or use the online ticket-entry system, then wait your state’s required time for facility owners to mark their lines before you dig:

  • State Name: Wait two full business days, excluding weekends and legal holidays.
  • State Name: Beginning at 7 a.m. on the next business day, wait 48 hours excluding weekends and legal holidays.

Pre-mark your proposed excavation area with white paint, flags, and/or stakes before you contact 811.

Wait for utilities to be marked before digging. Once utilities are marked, respect the marks, hand expose to verify location, and dig with care.

Always contact your state 811 center before digging and for the most current requirements.

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

case studies underground lines 2

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

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, electric, 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.

If you contact a natural gas pipeline or suspect a gas leak, take these steps:

  1. Warn others and leave the area immediately.
  2. Do not use matches, lighters, or anything electrical–even a phone. A spark could ignite leaking gas.
  3. Do NOT attempt to stop the flow of gas or fix the pipeline. Leave the excavation open.
  4. When you have reached a safe distance away, report the incident:
    • Call 911 immediately if you suspect a gas leak. Federal code requires this.
    • Call {Utility Name} at {XXX-XXX-XXXX} if you suspect a gas leak or contact a pipeline, even if damage is not apparent.
  5. Stay far away and upwind from the area until safety officials say it is safe to return.
  6. Report the incident to your supervisor.

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

Gas line explosion

Learn the warning signs of a gas pipeline leak.

{Utility Name} puts the safety additive mercaptan in natural gas, giving it a distinctive odor and making it easier to detect. However, in some instances this odor may fade, or you may not be able to smell it. Additionally, gas in some transmission pipelines may not be odorized.
So don’t rely on your nose alone. Use your senses of sight, hearing, and smell to detect a gas leak. Here are the signs:

  • A distinctive, sulfur-like or rotten-egg odor
  • Continuous bubbling in water
  • A hissing, whistling, or roaring sound
  • Dead or dying vegetation (in an otherwise moist area) over or near a pipeline
  • Dirt blowing into the air from a hole in the ground
  • An exposed pipeline after an earthquake, fire, flood, or other disaster
  • A damaged connection to a gas appliance

If you observe any of the above conditions, call 911 and the {Utility Name} emergency phone number at {XXX-XXX-XXXX} or your local gas utility from a safe location.

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, electric, 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.

If you contact a natural gas pipeline or suspect a gas leak, take these steps:

  1. Warn others and leave the area immediately.
  2. Do not use matches, lighters, or anything electrical–even a phone. A spark could ignite leaking gas.
  3. Do NOT attempt to stop the flow of gas or fix the pipeline. Leave the excavation open.
  4. When you have reached a safe distance away, report the incident:
    • Call 911 immediately if you suspect a gas leak. Federal code requires this.
    • Call {Utility Name} at {XXX-XXX-XXXX} if you suspect a gas leak or contact a pipeline, even if damage is not apparent.
  5. Stay far away and upwind from the area until safety officials say it is safe to return.
  6. Report the incident to your supervisor.

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.

{Utility Name} puts the safety additive mercaptan in natural gas, giving it a distinctive odor and making it easier to detect. However, in some instances this odor may fade, or you may not be able to smell it. Additionally, gas in some transmission pipelines may not be odorized.
So don’t rely on your nose alone. Use your senses of sight, hearing, and smell to detect a gas leak. Here are the signs:

  • A distinctive, sulfur-like or rotten-egg odor
  • Continuous bubbling in water
  • A hissing, whistling, or roaring sound
  • Dead or dying vegetation (in an otherwise moist area) over or near a pipeline
  • Dirt blowing into the air from a hole in the ground
  • An exposed pipeline after an earthquake, fire, flood, or other disaster
  • A damaged connection to a gas appliance

If you observe any of the above conditions, call 911 and the {Utility Name} emergency phone number at {XXX-XXX-XXXX} or your local gas utility from a safe location.