Erick Marciano was stopped in his SUV, heading to a meeting Tuesday afternoon, when he saw a runaway car go blazing through a red light, followed by police in hot pursuit.

Not thinking much of it, he turned left onto René-Lévesque Boulevard from Berri Street when his light turned green.

Then he saw the speeding car make a U-turn in front of him, barrelling back in the opposite direction — and toward a crowd of pedestrians and construction workers at the intersection.

"I didn't want him to hurt anybody," Marciano told CBC Montreal's Daybreak. "I figured, sacrificing a car was really no big deal. And that's what I did."

Honking his horn, Marciano swerved his SUV over the median, blocking the lane in front of the speeding car.

The vehicle slammed into the passenger side of his car. Only the suspect was injured.

Now, police are hailing Marciano as a hero for protecting the dozen or so pedestrians who were in harm's way.

Watch Marciano describe what went through his mind as he blocked the car:

Erick Marciano describes what went through his mind as he blocked a car that was in a police chase from slamming into pedestrians. 0:59

Heat of the moment decision

Marciano said the intersection was busy with people going to the nearby CHUM superhospital, workers out on their lunch break and ever-present construction workers.

"It came into my mind, I said: 'this isn't going to happen here," he said.

Erick Marciano used his SUV to block a speeding car. It was heavily damaged, but his insurance company said it will not hold him responsible for the crash. (Simon-Marc Charron/Radio-Canada)

He said he wasn't thinking about his own safety in the moment, but was confident his truck could take the hit.

"I figured, he had a Honda, and there was no way he was going over the median," he said. "For me, that was the safest thing to do."

After the crash, he said the suspect's vehicle was still running, its wheels spinning slowly in the snow.

Police arrested the 19-year-old driver at the scene. He appeared in a Montreal court Wednesday afternoon and was charged with several criminal offences.

Those offences include dangerous driving, impaired driving, failing to stop for police, driving a stolen vehicle, assault with a weapon, driving with a suspended licence and breaking conditions.

The suspect's mother attended the court appearance. She thanked Marciano for intervening and said her son has struggled with mental health issues since he was a child. The government needs to take mental health issues more seriously, she said, and it shouldn't take this kind of incident for her son to get help.

Damage 'doesn't matter,' he says

After the crash, Marciano spent the next three hours in a cruiser as he waited to be interviewed by grateful police.

"They were very, very thankful. Very thankful. Too thankful — it was embarrassing!"

He said his family was shocked when they heard what he'd done, but were also supportive.

Montreal Mayor Valerie Plante tweeted her thanks Wednesday morning, saying that his "heroic gesture saved the lives of many pedestrians."

His SUV was heavily damaged in the collision, but Marciano's insurance company told him Wednesday morning they were not holding him responsible for the crash.

"What matters is the outcome, and everything's well, and everybody could go home last night."

Listen to Erick Marciano's full interview here: