A Pennsylvania State Police fire marshal will investigate today, Bradnick said.
Brown, his wife and two young children live in the house, though nobody was inside at the time of the fire, he said.
Neighbor Rick Wilson, who lives two houses down from the Browns, said he had just finished eating lunch when he heard what sounded like a car crash on nearby Falling Spring Road.
When he ran outside to investigate, he heard another explosion and shattering glass and realized it came from the Browns' home.
Wilson and his father, Bob, grabbed two garden hoses nearby and started spraying water into the garage while his mother, Pat, called 911.
"We were putting as much water as we could into the garage with two garden hoses," Wilson said.
By the time the first fire truck arrived, there was heavy fire and smoke in the garage and on the first, second, and lower levels of the home, Bradnick said.
The fire spread through the heating ducts throughout the home, which made it difficult to put out, Bradnick said.
Firefighters were at the scene until about 6 p.m., he said.
Two firefighters were treated for minor injuries on the scene, he said.
A damage estimate had not been determined Monday night, but the house was insured, Bradnick said.
Firefighters dumped the charred remains of bicycles, pieces of furniture, a lawn mower and a grill, among other contents that were stored in the garage, into a pile in the front yard.
Brown said he had no idea what could have set off the explosion. He said he had nothing out of the ordinary stored in the garage.