Hard to tell at this point. I know when I was in college I was a lab assistant and went in to work on a Saturday. Someone had left a gas line to the bunsen burner on (without the burner hooked up) and I went into a lab that was a "bomb" in the making. I had the sense to evacuate and call for help. They turned off the gas from the outside and eventually opened up the building.
Those gas lines are often on timers now. Still can cause problems, though.