Shortly before 1:30 p.m., the suspect's vehicle tumbled down a hillside off San Gabriel Canyon Road and flipped over onto its roof just steps away from the waterline of the Morris Reservoir.
Azusa police, who were involved in the pursuit, were joined by Los Angeles County sheriff's deputies and firefighters who responded to the crash site.
A sheriff's helicopter hovered overhead as several firefighters and deputies made their way down to the wreckage. They removed one of the vehicle's doors in an effort to reach the unidentified suspect, who was pronounced dead at the scene.
The circumstances that led to the police chase were unclear.
DEVELOPING: More details will be added to this report as they become available.