Ottawa police are investigating a fatal collision between a cyclist and a car in downtown Ottawa Tuesday morning.

Paramedics said they responded just before 9 a.m. to Queen Street near Metcalfe Street, where they found a female in her thirties with serious head injuries and no pulse.

They said they inserted a needle into her chest to try and re-inflate a collapsed lung, along with a breathing tube and IV treatment.

She was taken to hospital where she was pronounced dead. Paramedics said she was wearing a helmet but it didn't prevent her fatal head injury.

Witnesses said the woman was hit by the door of a parked car and knocked off her bike, into the path of an oncoming car.

"I heard a lot of people just shouting and screaming," said Shawki Abdelmalik. "She was under the car, under the wheel and they were trying to pull the car off of her just to get her out."

Cyclists said they fear being hit by a door when they're biking.

"Everytime I see something like that I think it could be me," said Phil MacAdam. "A lot of motorists don't stop to see if a cyclist is coming when they open their door."

"You really have to ride defensively," said Nathan Comeau, who said he had been "doored" before. "The door clipped my bicycle and I flew over my handlebars and into the street, so a car could have run me over."

Police said they are investigating and considering laying charges, with Queen Street closed between Bank Street and Metcalfe Street until just after 1 p.m.

With a report from CTV Ottawa's Joanne Schnurr