The Langley drug section has taken control of the investigation into a suspicious blaze that tore through a three-unit townhouse complex overnight.

The devastating fire -- which injured two people and killed some family pets -- began with an explosion that shook the building and sounded "like a bomb."

"I called 911 immediately and said 'I think a bomb went off.' It shook the entire house. I literally thought we were being bombed," said resident Kiersten Dueck.

Neighbour Vern Eastman ran next door after hearing the blast at his friend's home.

"I looked out my window and I can see his garage door had blown up and there are pieces of his garage all over my driveway," Eastman told CTV Morning Live.

The structure was fully involved when crews arrived, with flames shooting through the windows and out of the roof.

"Quite a bit of mayhem here," Bruce Ferguson, Deputy Fire Chief of the Langley Fire Department, said. "There is evidence of an explosion here."

Eastman said one resident in a unit had broken a window to escape the burning building but still couldn't get out. That's when he jumped in to help.

"Finally I kicked the door in and he was badly burned," he said.

The Good Samaritan ran into one of the smoke-filled homes, going upstairs to find the man's wife and children running down the stairs.

"His animals were unfortunately in there and they didn’t make it. It was a pretty tragic night," Eastman said.

It appears the fire started in the middle unit garage of the three-unit complex. Langley RCMP say that's where two men were found, suffering severe burns.

Both were taken to hospital for treatment, one of them by air ambulance. A third person was checked out by first rmedical professionals and released, unharmed.

Cpl. Holly Largy said a structural engineer is needed to determine whether it's safe for police to investigate.

Multiple containers of butane were found on the lawn, and members of the drug squad put at least one can into an evidence bag.

"Police believe there may have been a butane extraction site established in the center garage and will continue their investigation in this regard," Largy said in a statement.

While officers have not yet said why there may have been butane extraction going on in the home, the process can be used to extract oil from marijuana.

Firefighters did rescue several animals from the stubborn fire, including a six-year-old cat named Burrows. Crews used a specially-fitted oxygen mask to revive the feline.

The cat’s owner, Dueck, 22, has lived in the complex since she was a toddler, and says she's lost everything.

"Everything I own, except for my animals and what I'm wearing right now," she said.

Dueck said she and her cat and two dogs will stay with her father until she figures out what to do. She says she's "very grateful" to the firefighters who rushed in to save her pets.

Victim services members from the Langley RCMP are providing support to the three families displaced by the fire.

"It's very, very traumatic," Eastman said. "All these families have lost everything. I don't really know what else to say."

With a report from CTV Vancouver's Nafeesa Karim and Maria Weisgarber