6th victim dies in Pennsylvania house explosion: Officials

A sixth person has died days after a house exploded in Pennsylvania, officials said.

Paul Oravitz, 56, died earlier Wednesday at a local hospital, Plum Borough officials and the Allegheny County Office of the Medical Examiner said.

Four adults and one adolescent were also recovered from the debris, officials said.

The Plum Borough officials and the Allegheny County Office of the Medical Examiner identified them as Casey Clontz, 38; his son, Keegan Clontz, 12; Heather Oravitz, 51; Kevin Sebunia, 55; and Michael Thomas, 57.

The cause and manner of death are pending.

Several homes were destroyed when the explosion occurred Saturday morning in Allegheny County, officials told reporters during a press conference on Sunday afternoon.

Two people injured in the incident were transported to local hospitals and have since been released.

During the initial response, 57 firefighters were treated on the scene for "minor issues" and all returned to duty that day, officials said.

It is unclear what caused the explosion, and the investigation is expected to be "slow and long," officials said. A representative from the gas company said pressure and smell checks done in the area indicate that the "system was operating as designed" at the time of the explosion.

Police received a 911 call reporting a house explosion and house fire at approximately 10:22 a.m., Allegheny County officials said.

One house appears to have exploded, with two others becoming engulfed in flames, according to Allegheny County spokesperson Amie Downs.

Three structures have been destroyed and at least a dozen more are damaged, including with windows blown out. Debris was scattered over lawns and the street in the area.

First responders found people trapped under debris, Downs said. Recovery operations were halted on Saturday afternoon due to severe weather in the region.

The cause of the explosion and fire is under investigation, Steve Imbarlina, the assistant chief for Allegheny County emergency services, said. Police are investigating the incident, he said.

The incident occurred in the borough of Plum, in the Pittsburgh metropolitan area. Video captured at the scene showed several homes on fire in the community of Rustic Ridge.

The borough of Plum urged people to stay away from Rustic Ridge in the immediate aftermath of the explosion.

Eighteen fire departments responded to the scene, which remains active. Allegheny County Emergency Management officials and the Allegheny County Fire Marshals are at the scene as well.

A woman filming a game at the municipal baseball fields shortly after 10:20 a.m. captured the boom of the explosion, a little under a mile away, according to footage she posted on Facebook.

Plum is located about 18 miles east of Pittsburgh.

ABC News' Victoria Beaule, Peter Charalambous, Matt Foster and Jessica Gorman contributed to this report.