Fire destroyed this house at 129 Germaine Road in Butler Township on Saturday morning. A man who suffered severe burns was flown by medical helicopter to West Penn Hospital in Pittsburgh. Three others also were injured in the fire.

BUTLER TWP — Police suspect a methamphetamine lab operation caused a fire Saturday morning that destroyed a Germaine Road house and injured four people.

Investigators believe the fire started in the basement of 129 Germaine Road and was caused by illicit activities, Butler Township Fire Marshal Larry Christy said Sunday.

Residents told police that there were three people in the basement who did not have permission to be there when the fire broke out around 6 a.m. Saturday, Christy said.

One or more of the intruders knew the family and may have had knowledge of how to get into the house, he said. Their names were unavailable Sunday as police continued to investigate.

The house is owned by Andrea Day, who lived there with her son Shawn Day. Both were treated for smoke inhalation, but were doing OK Sunday, Andrea's daughter Heather Day said.

A man who suffered severe burns was flown by medical helicopter to West Penn Hospital in Pittsburgh.

A fourth person was treated for smoke inhalation.

Sheri Hixon, who lives down the street with her husband, Phil, said that she was awake around 6 a.m. and heard a man screaming for help.

“My dog started to bark at 6 and I heard a man outside saying 'help me, God help me,'” Hixon said.

She immediately called 911 and tried to comfort the man until an ambulance arrived. Meanwhile, smoke was “billowing” out of the house, which erupted into flames within minutes, she said.

She described the burn victim as a white man in his mid-20s. He was wearing pants and shoes, but no shirt.

Though the man told emergency responders that the fire started when he was attempting to fill a kerosene heater, investigators found no evidence to confirm that claim, Christy said.

“Upon further investigation, we began to find signs of things that were not supposed to be there,” Christy said.

The state police Clandestine Lab Response Team was called to collect evidence from the basement Saturday afternoon and they are assisting Butler Township police in investigating, Christy said.

Christy said that his report will show that the fire was accidental in nature, but a criminal investigation will continue.

A dog died in the fire and fire crews were unable to locate several cats that lived there.

Neighbors said Sunday that the residents of the house were in the process of moving to Florida.

The road, which ends in a dead end and runs parallel to Calvary Cemetery, was described as quiet and peaceful — not an area where drug manufacturing was likely to be going on.

“It is a very quiet neighborhood,” Hixon said.

On Sunday, the property was surrounded by police tape and a sign on the door said that the building was condemned.

The house is considered a total loss and Christy estimated the damage to the structure and contents at $250,000.

The fire started in the basement, but quickly worked upward, causing the floor, and eventually the roof, to collapse. An attached garage was also damaged.

There was a partially-loaded moving trailer in the driveway. The trailer and its contents were not damaged.

Fire crews remained on scene until about 2 p.m. Responding to fight the fire were the Mercer Road, South Butler, Butler Township Station 3 and Unionville fire departments.

Eagle staff writer Andrew Carr contributed to this report.