A motorcycle crash causing life-threatening injuries, a teen who crashed his car because he had been stabbed and yet another motorcycle crash all bizarrely intersected during a three hour period on the RHVP Thursday night.

The first incident happened around 10 p.m., when a 23-year-old man was driving a motorcycle northbound on the Red Hill Valley Parkway near Mud Street.

As the driver approached the Greenhill Avenue exit, the motorcycle collided with a car being driven by a 21-year-old man. The impact caused the motorcyclist to lose control, police say, before his bike struck a guardrail and he was thrown into the road.

Police and ambulance crews responded and the man was rushed to hospital with life threatening injuries. Police say that alcohol and speed have not yet been ruled out as factors in the crash.

Then around 11 p.m., another crash happened while police had closed off lanes at the scene of the first crash. A driver was trying to merge into an open lane when another motorcycle rider slammed into the back of his vehicle, police say.

The rider was thrown from the bike into the road. Luckily, police and paramedics were already there, and treated the man at the scene for minor injuries. Charges are pending, police say.

Then just after 1 a.m. at the same location, while police were still collecting evidence from the first accident, a car crossed over the centre lane and crashed into a police cruiser that was parked with its lights flashing.

When officers opened the car door, they found a 17-year-old man suffering with stab wounds. Const. Steve Welton told CBC News that the victim may have lost consciousness before slamming into the cruiser.

The teen was taken to hospital with serious, but non-life threatening injuries. According to police, the teen had been stabbed a little earlier during a fight between two groups in a parking lot near 674 Queenston Road.

The investigation into that incident is still ongoing, police say.

"The unpredictable nature of policing remains a constant in the profession," Welton said.

adam.carter@cbc.ca | @AdamCarterCBC