London police are investigating a serious collision in the east end of the city that has left one person dead.

Police say the single-vehicle crash occurred just before 6 a.m. on Clarke Road north of Dundas Street.

A Mini Cooper was travelling southbound when, investigators say, it somehow lost control and hit a large treee. The driver's-side door was the point of impact.

The crash occurred in front of Wally Dennett's home. He had awoken around 5:45 a.m. then suddenly heard a huge bang.

He went outside with his son and says inside the car they found the driver they described as a young man unresponsive.

"[My son] was yelling at the driver window and I was yelling in the sunroof and there was no response," Dennett says.

Police have confirmed a 28-year-old man has died in the collision, but no further details have been released.

Investigators remained at the scene most of the morning, removing the car around 10 a.m.

Clarke Road was closed in both directions from Dundas Street to the train tracks north of Avalon Street for the police investigation, but has since reopened.