Catherine Plasse-Ferland said agreeing to have lunch with a total stranger may have saved her life.

Plasse-Ferland was sitting by a cafeteria window, in the building where she works in Quebec City's Saint-Roch neighbourhood on Wednesday, just minutes before a car came crashing through it.

"I had a guardian angel," said Plasse-Ferland — a woman who suggested she join her on the rooftop patio, on what was one of the first warm, sunny days after a cold, wet spring.

Other witnesses also said the mild weather may have had a significant impact on the outcome of the crash, which left 12 people injured, three of them seriously.

The car came to a halt inside the cafeteria of the six-storey building, at the corner of Charest and Langelier boulevards, and burst into flames just before 1 p.m. ET.

According to witnesses, two cars collided at the busy intersection, projecting one through the cafeteria's front window.

"I think everyone involved was really lucky," said Francis Major, who works for Umaneo, a software company in the building.

The building houses a shared office space, called La Station. All of its people "were eating outside or were on the terrace," Major said.

Likewise, Major and his colleagues were taking part in a music class at the back of the building when the crash happened.

"It's the only day of the week that we aren't all in the cafeteria," said Major, a trained first responder, who quickly stepped in to help the injured.

He said he found a man and a woman pinned between the car and the back wall of the room. No sooner had he helped them and the vehicle's driver get outside and the car exploded.

"It wasn't like in the movies, but almost," he said.

Speeding driver crashes into a car in opposing traffic, then crashes through window of lunch room at office building - 12 injured including both drivers. <a href="https://t.co/umeTd9MyWU">pic.twitter.com/umeTd9MyWU</a> —@CatouCBC

Car allegedly speeding

Others also rushed to help. Jean Morissette was sitting with a group in a conference room next to the cafeteria when he heard what sounded like an explosion.

"When we went out we saw a woman laying on the ground," said Morissette, who pulled that woman out of the building shortly before the explosion.

"She was in a state of shock. She was pale — I'm really worried about her," he said, hours after the incident.

A car crashed through the cafeteria on the main floor of the six-storey building just before 1 p.m. ET Wednesday. (Submitted by Lina Dubuc)

Quebec City fire Chief Bill Noonan said 12 people were sent to hospital, although none sustained life-threatening injuries.

Hospital officials said three of them are in serious condition. The drivers of both vehicles are among the injured, police said.

The building was evacuated, but the fire was quickly extinguished, said Noonan.

While the structure was not compromised by the damage, people living in the building's condominiums won't be able to go home until at least 9 p.m., while accident reconstruction experts carry out their investigation.

3rd car rear-ended

The crash may have involved more than two vehicles.

Eyewitness Diane Poitras said she was driving her car a few blocks up the street when she was rear-ended by a grey SUV.

"His vehicle was stuck in my rear bumper," said Poitras.

"When he managed to get free, he sped off, and he was swerving between vehicles," she said.

Moussa Sangaré's was sitting in his office, which is located right behind the cafeteria, when the car slammed into the building. (Catou Mackinnon/CBC)

Several eyewitnesses also told CBC News about the SUV, seen speeding on Charest Boulevard in the minutes preceding the crash.

Moussa Sangaré, whose office is just behind the cafeteria, saw the driver get out of his vehicle.

"He was really in a state of shock," said Sangaré, describing him as "dazed" but seemingly not seriously injured.

Sangaré said he thought the entire building was crashing down on him, concluding the driver "had to be going fast."

"He jumped the sidewalk, went through two rows of tables and went all the way to the sink at the back of the room."

Quebec City police spokesperson Cindy Paré said investigators are questioning several eyewitnesses to determine what happened.

"All theories will be analyzed," said Paré.

Charest Boulevard remains closed between Marie-de-l'Incarnation and de la Couronne streets. Paré said people should avoid that area for the rest of the day.

