Fire investigators are working to determine what cause an early morning fire inside a residential garage on Main Street in Port Jefferson Thursday morning.

"I was really nervous. I didn't want to open the door because I thought maybe they were gunshots," neighbor Jeanne Kulich explained. She, like others in the area awoke around 6 a.m. to disturbing noises.

"There were a lot of explosions and really loud booms," added Sadie Lapresti, who lives next to the property the blaze spread to. Her family was concerned the fire would spread to their home.

Fire officials say the fire originated in the detached garage where two cars were located. A car in the driveway also caught fire before it spread to the home and several trees on the property.

It took about an hour for six fire departments to get it under control. Port Jefferson firefighters lead the effort.

Christian Neubert, assistant chief for Port Jefferson Fire Department said, "the biggest challenge we had was the extension to the house and it's an old house and there's been some remodels within the house so finding the fire within the house was probably the biggest challenge we had."

Radiant heat was the reason a nearby home suffered exterior damage.

A Port Jefferson firefighter sustained a hand injury and was brought to Stony Brook University Hospital for treatment.