Janesville Police are investigating a fatal single-vehicle crash that occurred early Saturday morning.

Sergeant Drew Severson says officers were dispatched to East Court Street and Atwood Avenue shortly after 2:30 a.m.

Severson says the driver was west on Court Street when they failed to negotiate a curve and struck a tree.

Severson says speed and alcohol are believed to be factors in the crash.

The name of the victim is not being released at this time.