WALNUT CREEK — Police are investigating the death of a man whose vehicle struck a tree on Ygnacio Valley Road early Saturday morning.

Walnut Creek police provided little information about the crash, other than to say in a news release that it took place at about 2:40 a.m. Saturday. A vehicle of an unspecified make was traveling east on Ygnacio Valley Boulevard when, for an unknown reason, it crashed into a tree, just west of North Main Street.

No other vehicles were involved and the driver, the only occupant of his vehicle, died at the scene. Walnut Creek police said no further details would be released over the weekend, including the identity of the deceased. But anyone who has information about the crash is asked to call the police department at 925-943-5844 or its anonymous tip line at 925-943-5865.