Detectives are investigating a collision that critically injured a 30-year-old man near an encampment in South Lake Union on Tuesday.

Police responded to the crash at Dexter Avenue North and Mercer Street around 3 p.m., according to a statement from the Seattle Police Department. Seattle fire medics transported the man, who lives at the encampment, to Harborview Medical Center in critical condition, police said.

The driver of the vehicle left the scene, and later called 911 to report the incident. Both the driver and the one passenger in the vehicle were cooperative with investigators, police said.

Because of the “seriousness of the victim’s injuries,” police added, the department’s homicide unit is leading the investigation.

No further information was immediately available.