Halifax Police are trying to piece together what led to an early morning crash in Halifax Friday .

Officers were called to the intersection of Chebucto Road and Windsor Street around 3:30 a.m., after a report of a single vehicle crash.

Once on scene, police located a 20-year-old man unresponsive in a Toyota Echo.

Emergency crews removed the man and transported him to hospital, where he remains in serious condition.

At this time, police say they do not know what led to the collision.