Austin house explosion: Investigation continues into cause

AUSTIN, Texas - Investigators are still working to figure out what caused a home to explode in Northwest Austin on Sunday.

PREVIOUS COVERAGE: 6 injured, at least 24 homes damaged after house explosion in Northwest Austin

The explosion also damaged at least two dozen homes and injured six people.

The incident

What we know:

The explosion happened on April 13, around 11:30 a.m. in the 10400 block of Double Spur Loop, just off DK Ranch Road, north of Laurel Mountain Elementary.

When crews arrived, they found a two-story home that looked like it had exploded and been leveled to the ground. The house next door also suffered severe damage.

There was a vehicle fire at the home that collapsed, and fire crews extinguished small spot fires in the collapsed debris as well.

Six people were hurt in the blast, including two who were inside the home that exploded and who, as of Sunday, were in critical and in serious but stable condition. A third person from the house next door was also in critical condition.

A fourth person with minor complaints refused transport from the scene. EMS also treated two firefighters for minor injuries.

The home was recently built in the Great Hills neighborhood and belonged to a husband, wife, and their two children. A person who knows the family posted the husband, who was in the home at the time of the explosion, is in the hospital with burns and broken bones and that he had to undergo surgery. 

What we don't know:

The cause of the explosion is still unknown.

Investigators with the Travis County Fire Marshal's office spent Monday combing through debris, collecting evidence and trying to determine what caused an explosion so powerful that it could be heard as far away as Georgetown. 

Authorities say there were propane tanks at the home that exploded, but at this point it's unclear if that was to blame. 

"No underground gas service to any of these residences," said Assistant Chief Thayer Smith of the Austin Fire Department. "Right now, there is no intent that there will be a criminal investigation."

What's next:

The Travis County Fire Marshal's office sent out a statement saying it will not release any further information on a possible cause until the investigation is complete. 

"Until the investigation is complete, this office will not release any information or speculate on causes," said Travis County Fire Marshal Gary Howell. "We appreciate the public's understanding and patience."

Attorney speaks on house explosion

What they're saying:

"My initial thought when I saw it was, I can't believe people weren't killed, and I hope that the people who are seriously injured survive because it's a very serious situation," said Michael Lyons. 

Attorney Michael Lyons with Lyons and Simmons Law Firm has experience handling cases like these, including the recent verdict, securing $109.5 million in a lawsuit against CPS Energy for a home explosion in Bexar County. 

"This, unfortunately, is way too common," said Lyons. "These houses blow up, whether it be natural gas or propane, all too common, it's a very serious problem." 

Lyons said he sees house explosions happening more frequently, especially in Texas, in part due to aging infrastructure. 

Austin Fire stated the neighborhood does not have underground gas service, but it does have propane tanks. 

"I would say the most likely, the most probable thing would be a propane explosion," said Lyons.

Lyons believes it is likely there was a leak that developed over a significant amount of time and said ignition could be something as simple as a doorbell or static electricity. 

"To have this type of magnitude explosion means you've got the saturation of that environment. Likely that entire house is full of gas when some ignition source lights it," said Lyons.

When there is a natural gas or propane leak, the initial question is, why didn't anyone smell anything? There is typically a strong rotten egg smell. 

"People that are exposed to gas that's even treated with mercaptan oftentimes experience something called odor fatigue, where, over a period of time, you may not actually smell it," said Lyons. "You become desensitized to it."

Dig deeper:

Laurel Mountain Elementary School is not too far away from the neighborhood, and they felt it there. 

"Laurel Mountain Elementary sustained some damage from the explosion—the windows of the cafeteria and one classroom shattered, and there was damage to the electrical and plumbing in one of the portables. Two classes of students were relocated to other areas of the school today, but the campus otherwise operated on a normal schedule," said a spokesperson for the school.

"People just need to put their insurance carriers on notice that they've suffered property damage and tell them that this has happened and get an appraisal to see what the extent of the damage is," said Lyons.

Nearby residents react

What they're saying:

"You can't really wrap your head around it until you see it," said neighbor Christine Miller. "There was this huge boom and then the house shook."

"It was like a shock that ran through you," said Chris Broadbent who lives nearby. 

On Monday, residents of the other damaged homes—including one next door that partially collapsed—began the long cleanup process. 

"It's shocking to see the scope of damage and how widespread the debris field is," said Matthew Cronk, who lives nearby. 

"The garage doors all got blown in," said Carol Hassell, whose home was damaged by the explosion. "All my windows had blown out, the front door, and there's extensive damage to some of the ceilings in my house."

"I'm okay. I'm glad I wasn't hurt at all," said Hassell. 

Even though the damage is widespread, many neighbors are breathing a sigh of relief, knowing that all of this could have been much worse. 

"Miraculous that nobody was killed," said Cronk. 

"Now that I see this debris and somebody was in the house when that happened, I'm shocked, I am happily shocked that they are not deceased," said Miller. 

Northwest Austin