Houston has gas piplelines all over the place, some of them enormous. We even have a couple of subterranian dirt submarines roaming around underground drilling even more pipelines 24/7. People in the neighborhood, apparently not very smart people because they didn't report it to the authoritiies, said they smelled natural gas all day. The tank that exploded with incredible ferocity was supposedly empty, indicating some kind of gas must have collected inside of it. The feds say they will not have a report on the cause for several weeks due to the extensive debris that has to be cleared. Nine people were injured, none seriously. The eveining shift supervisor was locking the door after the last employee left when the explosion occurred. If it had happened twenty minutes earlier a lot of people would have been killed. That raises my eyebrows a little. The timing seems like something an arsonist who didn't necessarily want to kill anybody would have planned.