Explosions at a Toronto propane facility forced thousands of people to evacuate early Sunday, and witnesses described an enormous fireball that lit up the sky for miles. One firefighter died.

Firefighters were battling blazes at the Sunrise Propane Industrial Gasses facility hours later. A worker at the plant was unaccounted for, Toronto police spokesman Mark Pugash said. Some residents suffered minor injuries.

Toronto fire services division chief David Sheen said the veteran firefighter died at the scene, though cause of his death was not immediately known. He was later identified as Bob Leek, a district chief of emergency planning.

"It's hard," Sheen said, his voice cracking. "I'm sure all of our guys are having a rough time with it."

Ontario Minister of Community Safety Rick Bartolucci said the fire continued to burn Sunday evening but is under control. The cause is under investigation.

The explosions early Sunday blew out windows blocks away and also shut down Canada's busiest highway and a part of the subway system, snarling traffic for thousands of travelers. Mayor David Miller said the chance of another explosion still exists because it is a propane facility.

Some residents said the blast was so forceful they felt their homes rock as though they had been struck by an earthquake.

"It was just a tremendous explosion and blew all the windows out of the house, just blew the house up, and I just managed to get out of there in time," said Robert Helman, who was covered in cuts and bruises as he fled his home.

Fearing the air had turned toxic, police used bullhorns to order the estimated 12,500 residents within a mile (1.6 kilometer) radius of the plant to flee their homes immediately. Air quality tests later in the day showed the fumes were not toxic.

About a dozen terrified residents — some clad in pajamas and housecoats — found their way on foot to nearby Yorkdale shopping mall, where security personnel offered them water and a place to rest.

Toronto fire services division commander Bob O'Hallarn saw at least five heavily damaged homes and said windows were blown out a fair distance from the scene. He also saw large pieces of metal on the street and said it looked as if they were from tanker trucks.

Sunrise offered condolences to Leek's family and colleagues and said company officials are praying that their missing employee is still alive.

Officials said a witness saw the employee move toward the explosion.

"At present, we do not know anything about how the explosions occurred and we are waiting to learn about its cause," the company said in a statement.

Many residents were evacuated to a nearby university. Deputy Mayor Shelley Carroll said Sunday night residents can begin returning home. Where homes are found to be uninhabitable, residents will be escorted back to shelters.

Miller said authorities are reviewing why the propane facility was allowed to be built near a residential area.

Some people raced out of their homes, grabbing only their loved ones and pets. Others piled into cars to drive out of the area.

Beatrice Zampini, 48, wiped away tears as she sat in Yorkdale mall's makeshift emergency shelter, her teenage son and daughter by her side. Her daughter Daniela, 19, woke up to the explosion, which sent her ceiling light crashing to the ground. She fled outside with her family, only to find the street teeming with panicked neighbors.

"Everyone was just running down the street. It was like something from a movie," she said.

Ricardo Oliveira, 24, said his windows blew out and he saw a huge ball of flame hundreds of meters in the sky.

"We got freaked out. My family woke up. They thought it was a plane that went down," he said.

One fire official said the city's residents were "lucky."

"There was a very, very large amount of fire when we arrived and the extent of the explosion, if the blast was heard as far away as it was, could have been much more serious," Division Cmdr. Bob O'Hallarn said.

Many angry residents were demanding to know why such a facility was ever allowed in the residential neighborhood.

Josei Miceli, 59, who has lived there for 40 years says the area is full of elderly people who aren't mobile.

"We were concerned when this company moved at the end of the street," said Miceli. "But we weren't even advised that they were going to be there. They just moved in and we've been concerned since they were there that something like this would happen."