The Ontario Fire Marshal’s Office is investigating after an explosion and fire tore through a Woodstock home Friday afternoon, sending four people to hospital.

Officials say the Alberta Avenue house was fully engulfed when they arrived at the scene just before 5 p.m.

“It was like a real loud bang,” says neighbour Joanne Drummond. “We thought somebody actually hit our garage.”

All four people inside the home suffered burns while trying to escape.

They were sent to Woodstock General Hospital for treatment, and two were later transferred to London’s Victoria Hospital.

“There were firefighters everywhere,” says Jessica Dodd, “People all down the street were crying and watching in awe.”

Dodd and her husband Neil live across the street from the fire-ravaged home. He says he saw the garage door fly clean off its tracks and land on three cars.

That’s when the people inside came rushing out.

“I saw three of them running out of the garage door and one of them was covered in flames,” says Neil.

The Dodds, as well as several other neighbours, say they heard a loud explosion right before the flames broke out.

Officials note it’s too early to say how the fire started, but add damage is so extensive the entire house will have to be torn down.

According to the OFM, demolition will likely begin tomorrow while they continue to investigate.

Officials say two neighbouring homes also sustained heat damage to their exteriors.

One of those families says they were told to evacuate their house.