This incident reminds me a Major Incident in Queens in about 1966 or 67. It resulted in a 13-alarm fire in Jamica Queens when a leak developed in a large High Pressure Gas Main, the 1st units on the scene stalled due to the Gas Concentration being so high the apparatus did not have enough air to run. Most of the 1s Alarms apparatus was destroyed when the gas ignited. Also, a similar situation happen a few years ago in the San Francisco area. The gas mains in many areas are old and have never been replaced. Natural Gas is LIGHTER than air Propane in HEAVER than air., but either way both can find a sources of ignition easily, including due to static electrical charges building up in the escaping gas. This static charge is especially a danger when plastic gas line and pipes are used. Do you know how to handle these situations? In a gas cloud ensure that even your everything, including your radios and headphones, as mentioned above, are "Intrinsically Safe" in a gas environment in the explosive Range.
Captain Bob Rainey FDNY Engine 26 retired.