Harry Rashid was at the parade with his wife and two young daughters when he witnessed the collision.
"It happened about 10ft away from us...The vehicle came to our right. It emerged from just right next to an ambulance, which was parked up. This grey people carrier just pulled up from the right and just rammed into all the people at the side of us," he says.
Speaking to PA news agency, the 48-year-old says the car was travelling south, down Water Street.
"It was extremely fast. Initially, we just heard the pop, pop, pop of people just being knocked off the bonnet of a car."
He describes how crowds began trying to smash the car windows when the driver stalled, before he started moving again.
"My daughter started screaming and there were people on the ground."
"I saw people lying on the ground, people unconscious."
"It was horrendous. So horrendous."