Two teenage girls are dead and another two teens are in hospital with serious injuries after their car swerved off the road into a wooded area near Stittsville in southwest Ottawa on Sunday night.

Firefighters, police and paramedics were all called to Fernbank Road north of Jinkinson Road at about 9:22 p.m.

The four teens were in a black Chevrolet Cobalt and were heading to or from a bush party, according to Ottawa police Det. Alain Boucher. The driver was trying to pass another motorist when, for reasons so far unknown, the car swerved off the road and into the trees.

Paramedics say the two girls, both about 17 years old, were pronounced dead at the scene.

Ottawa police fatal crash Fernbank Road June 19 2017

On Monday morning, Ottawa police analyze the scene of a crash that left two teen girls dead and another two teens seriously injured. (Andrew Foote/CBC)

2 other teens still in hospital

The two other teens, a 17-year-old girl and an 18-year-old man, were sent to hospital with traumatic injuries. They were listed in serious but stable condition.

Only one of the four teens was conscious when firefighters arrived, they said, but it's not clear who that was. Investigators also don't know which teen was driving the car at the time.

The Ottawa police collision investigations unit is handling the case.

Fernbank Road remains closed from Jinkinson Road to Blacks Side Road.

Fatal crash on Fernbank Road0:25

Fatal crash Fernbank Road Ottawa Stittsville June 18 2017

A firefighter walks toward the scene of a crash that left two teen girls dead Sunday night on Fernbank Road. (Stephane Beaudoin/CBC)

Ottawa police cruiser fatal crash teens dead Fernbank Road June 18 2017

An Ottawa police cruiser blocks access to the scene on Fernbank Road. (Stephane Beaudoin/CBC)