Gas Explosion Larimore North Dakota illustrates dangers with propane and natural gas

Published on Apr 24, 2013 | by Gary M. Hazelton

The recent gas explosion in Larimore North Dakota serves as a reminder that propane and natural gas can be extremely dangerous.  Two adults were seriously injured and an infant killed when leaking propane was ignited by the spark created by a water pump switch.  We recently concluded a similar case where a valve in a gas line that served a gas clothes dryer in the basement of a home, recently purchased out of a foreclosure, was opened in belief that the line served a gas fireplace on the main floor.  The line spewed natural gas into the home for about 27 hours until it exploded demolishing the home and seriously burning two people.  Immediate investigation allowed us to determine the origin and cause of the explosion and preserve key evidence. 

We also learned during the litigation that uncapped gas lines were much, much more common in foreclosure properties.  The departing owners disconnect gas appliances and neglect capping the open end of the appliance line.  Current code requirements provide that valves must be located much closer to the appliance than former code provisions.  This helps prevent the problem of mistaking what appliance a valve controls.

For natural gas or propane to "explode" the concentration has to be within the explosive range for that gas.  That is, the concentration has to be between what is known as the LEL or Lower Explosive Limit and UEL or Upper Explosive Limit.  Anything that  moves or mixes the gas with the air in the structure, such as walking through a home after opening a door etc., can suddenly bring the gas within the explosive range.