A vast, intense wildfire that has forced more than 88,000 people to flee the Canadian oil city of Fort McMurray was spreading overnight, threatening the local airport and engulfing more communities, authorities said.

More than 1,600 homes and buildings have already been destroyed by the “heartbreaking” blaze, which has turned skies blood-red and rained ash on residents fleeing on crowded highways. More than 18,500 acres have already been scorched.

PHOTOS: Entire City Flees Raging Wildfire in Canada

The entire province of Alberta was under a state of emergency early Thursday as crews frantically battled wind-whipped flames that were heading towards more homes.

Local officials announced a mandatory evacuation late Wednesday of the communities of Anzac, Gregoire Lake Estates and Fort McMurray First Nation — which lie roughly 30 miles south of Fort McMurray.

“The fires that are surrounding Fort McMurray right now could go in any direction,” teary-eyed Alberta lawmaker Brian Jean told CTV. “My home is burnt to the ground but it’s just stuff. All my stuff, all my memories. I lost a son last year…”

Canada’s Prime Minister Justin Trudeau said the damage was “absolutely devastating” and said there’s a loss on a scale that’s hard to imagine.

With some neighborhoods already in ruins, dry and unseasonably hot conditions pushed walls of flame towards Fort McMurray’s airport, with webcam images showing black smoke engulfing a nearby hotel and an older airfield late Wednesday.

All flights had already been canceled to and from the city, which lies among the third-largest reserves of oil in the world behind Saudi Arabia and Venezuela.

The blaze has effectively cut Fort McMurray in two, forcing about 10,000 to flee north to the safety of oil sands work camps while the other 70,000 or so were sent streaming south in a bumper-to-bumper snake line of cars and trucks that stretched beyond the horizon down Highway 63. Some vehicles sat in ditches, the victims of engine trouble or a lack of gas.

Remarkably, there were no official reports of casualties except for a vehicle collision that Alberta Emergency Management Agency director Scott Long said hadn’t been confirmed as caused by the fire.

Image: Wildfire in Fort McMurray

Image: Wildfire in Fort McMurray

Danielle Larivee, Alberta’s minister of municipal affairs, said the fire was burning in residential areas of the city. A later update from the Wood Buffalo municipality said flames were continuing to claim homes and had destroyed a new school.

There were haunting images of scorched trucks, charred homes and telephone poles, burned out from the bottom up, hanging in the wires like little wooden crosses.

The evacuation was “just crazy,” oil worker Victor Howald told CTV. “There were people pulled over in ditches, thousands of pickups without fuel. It felt like the apocalypse.”

He added: “It was just raining ashes and you can’t see. You couldn’t see anything. There was only police cars and sirens going around trying to clear people out.”

Howald said he didn’t have enough gas to get out of town so he walked until eventually a stranger pulled over and offered him a ride out of town and he eventually he made his way to an evacuation center in Edmonton.

Shell said it has shut down production at its Shell Albian Sands mining operations near the city in order to focus on getting families out of the region. Suncor, the largest oil sands operator, said it is reducing production at its regional facility — about 15 miles north of the city. Many other companies evacuated non-essential staff.

Oil prices jumped early Thursday, Reuters reported, noting that prices were also affected by escalating fighting in Libya. International benchmark Brent crude futures were trading at $45.36 per barrel at 2.54 a.m. ET, up 74 cents or 1.7 percent from their last close, after three days of declining prices, it reported.

The city evacuation, ordered early Tuesday, was the biggest in the history of Alberta. Among those trying to escape was Callahan Scheffer, who told CBC how he and fellow bus passengers abandoned the vehicle and fled for their lives.

“We were sitting there, not moving, and you could see flames and ash sitting the side of the bus all of a sudden the grass between the two highways was catching on fire,” he said.

As flames began to catch the sides of the bus, passengers yelled at the driver to pull off to the other side of the road.

“As we were driving down, the front end ended up exploding. We kept creeping forward but then we all bailed out from the bus shouting ‘everyone get out, everyone get out!’

Scheffer added: “We all grabbed our bags and started running, taking off on foot. It was a little scary, none of us knew where they heck we were going. We ended up just running to the east just to get away. My nerves were shot at this point. I could see the heat.”

He said he jumped into the pack of a pickup with other strangers and the vehicle drove around a parking lot. “While we were getting away we could hear all sorts of explosions going off,” Scheffer recalled to CTV.