As dozens of people recover from a major pileup on B.C.'s Coquihalla Highway, a man who was on a Greyhound bus that was hit by a semi-truck says the collision felt "like an explosion."

"The driver said 'brace yourselves,' and we braced ourselves, not knowing what he meant and there was this huge crash that I can't even articulate," Jordan Kawchuk told CTV News Channel Monday.

"There (were) people flying all over the place and screaming and crying. It was surreal."

Kawchuk, who takes the bus to visit his daughters in Kelowna every month, said conditions were dangerously snowy when two Greyhounds, two semi-trucks and two passenger vehicles plowed into each other at the bottom of a slippery hill north of Hope Sunday night.

He remembers his bus nearly skidding off the highway in the moments before the pileup that sent 31 people to hospital in conditions ranging from stable to critical, including one victim who was trapped inside a vehicle when paramedics arrived.

"We took off at 5 (p.m.) and about three hours later, we skidded and kind of tilted, hanging off the road a bit," Kawhuck said. "People were yelling 'Go to the right. Go to the right,' so we could kind of not roll over."

Ten of those people remained in hospital Monday. Two were in serious condition, and eight were in stable condition.

The two Greyhounds involved in the crash were both travelling from Kelowna to Vancouver, according to Lanesha Gipson, a spokesperson for the bus line.

A bus with 47 people onboard flipped onto its side. The other Greyhound was carrying 50 passengers.

"When I got out of the bus and I turned around, it was just a sea of vehicles and smoke and cold air and snow and uniforms—it looked like a movie set," Kawchuk said.

In total, more than 160 people were involved in the crash. Those who were uninjured were taken to nearby warming centres.

For some of the victims, the crashes seemed to happen in slow motion as massive vehicles, apparently unable to stop, barreled toward them.

One such crash was recorded from within one of the Greyhound buses, showing passengers bracing themselves for a collision as a semi slides in their direction.

"Hold on, hold on, hold on, hold on!" a man can be heard yelling just before the impact.

The crash is followed by a wave of screams and cries.

The woman who filmed the collision, Lacey Shepherd, told CTV News it was just one of a number of crashes the passengers experienced before the chaos was over.

"It was just semi after semi into the back of the bus," said Shepherd, who was on the same bus as Kawchuk. "Almost tipped us over."

Shepherd and others were stuck on board the vehicle for hours before finally being taken away from the scene. Still, she said she feels fortunate to not be among the many victims who were seriously injured.

"[I'm] thankful to be alive. There's people that got pretty hurt," she said.

First responders were 'just wonderful': Kawchuk

Hope Fire Chief Tom DeSorcy said his department immediately recognized the seriousness of the call and other agencies, including Hope Search and Rescue and emergency crews from nearby Popkum, B.C., quickly became involved.

"It was just horrendous when they got up there—just a mass of carnage in terms of vehicles from the semi-trucks that were seemingly piled on top of each other and buses...that are on their sides," DeSorcy said.

"Organized confusion is the best way you can describe (it) when you have so many people involved, so many agencies involved and all working towards a common goal."

Between the icy roads and continuing snowfall, it was a challenging call for first responders, but Kawchuk described the rescue efforts as "amazing."

"I don't really have a grasp on how long they took because it all happened so fast, but in my mind, they came immediately and were so professional and so calm," he said.

"We had to exit the bus from the window on the side and I just remember kind of crawling down the ladder into the arms of a fire guy and feeling safe. They were just wonderful."

The two air ambulances dispatched to the crash were unable to land at the scene because of the weather.

Passengers with first aid training also did their best to help victims as they waited for emergency crews to reach them.

"I got off the bus, helped people to climb up from the embankment—it was like 10, 12 feet. It was steep. It was hard to get up," said Linda Davies, who quickly jumped into action after the Greyhound she was on was sideswiped by several semis.

"There was a woman at the front of the bus who was badly injured…obviously some broken bones—neck, pelvis, ribs. I stayed with her, kept her warm, reassuring her until the paramedics came."

The Ministry of Transportation issued a travel advisory just nine hours before the crash, warning drivers about poor visibility and blowing snow on the roadway.

According to Minister of Transportation Claire Trevana, the highway had been plowed just 20 minutes before the incident.

The crash closed a stretch of the Coquihalla overnight, but the busy highway was fully reopened shortly before 8:30 a.m. Monday as crews continued to clean up the mess of mangled vehicles left behind by the pileup.

With files from The Canadian Press, CTV Vancouver's Breanna Karstens-Smith, Nafeesa Karim, Michele Brunoro, David Molko and Scott Roberts