Cause of Johnson home explosion unclear

WILSON, N.Y. (WIVB) - It's been three months since the Johnson family lost their home and their 14-year-old daughter to a deadly explosion.

We now know through a lawsuit filed by the Johnson family that the day before their house exploded, they smelled what they thought could be a leak, opened the windows, shut off the NOCO tank behind their home and called NOCO Energy.

READ | The lawsuit filed by the Johnson family here

The Johnson's attorneys say they were never warned to stay out of the house and that NOCO never came to the house because the technician on the phone suggested it was probably just the odorant added to propane gas that they were smelling. It tends to smell stronger when the tank is low, which it was. NOCO also couldn't refill the tank at that hour because the billing office was closed.

MORE | What should you do if you smell gas? What should you do if your pilot light goes out? Find the answers and other propane safety tips here

Homeowner Jody Johnson didn't want to wait for NOCO to come inspect the tank, so that evening, he disconnected the cooper line from the 500-pound NOCO tank and hooked the line up to a small propane tank that he owned. The next morning, the house exploded, killing 14-year-old Sarah Johnson.

RELATED | See our full coverage of the home explosion, from the first story to subsequent stories of the community rallying to support the Johnsons in their hour of need

Niagara County Sheriff James Voutour says his office just finished its end of the investigation last week, and sent its findings to lawyers and insurance companies. The evidence will now go to a special lab in Syracuse for final review.

Sheriff Voutour says after months of investigating, there is still no glaring indication of what may have caused a gas leak in the home. He says we may never know.

The sheriff says many of the propane lines burned in the fire. Every propane tank had a regulator along the line, but that was never even found. It too may have disintegrated in the heat.

But investigators do believe whatever caused a leak, the propane naturally sank to the lowest point first, the basement, and investigators say they believe that when a tankless hot water heater in the basement kicked on in the morning, that ignition caused the explosion.

Michael Meath is a spokesman for the NY Propane Gas Association, who says propane is absolutely safe if used and checked properly.

"Anytime something goes wrong certainly everyone wants to know what might have happened. It has a tremendous track record," Meath assured.

Propane is used in more than two million homes in New York State and while it is possible for gas lines to go bad and just start leaking, most lines last for decades. But Meath says the rule to live by is if you smell what may be a gas leak, "Get out of the house and take your cellphone with you. Don't turn anything on or anything off as you walk out of the house."  Then call your gas supplier.

"If either you don't get satisfaction from making that phone call or you can't get a hold of them, then call 911 and you'll get some immediate assistance from the fire service, but this is not the kind of thing that you want to stay in your home," Meath said.

Never try to fix it yourself, officials say; leave it to a qualified service technician.