"A room only has to be filled with 25% of gas to explode," says former FDNY Division Chief Vincent Dunn.
Chief Dunn wrote the book, actually several books on fire safety and survival. His advice? If you smell gas, get outside. The next step to take is to call 911 immediately. Do not call 311, which is New York City's information line. The 311 recorded greeting instructs callers to dial 911 in an emergency.
If the gas odor is not strong, Chief Dunn says opening a window before exiting to ventilate is safe, but there are many things that are NOT safe. Do not flip on or off any light switches.
"Flipping a switch causes an arc," adds Chief Dunn.
The arc-ing can happen by flicking on a flashlight as well. Also, do not plug or unplug any electrical cords like a cell phone charger, which could explode.
Also, do not use an open flame to light a cigarette or a candle if you smell gas. If the power is out, Chief Dunn says many homeowners make the mistake of investigating on their own. Do not investigate the source of the gas smell or go looking for your shut-off switch - leave that to the professionals.
Lastly, if you detect the gas odor inside your garage, do not start the car in the garage. Doing so could ignite an explosion.
The most important thing to remember is to get out safely, then call 911 for help.