Updated 3:15 p.m.
One man was killed Monday morning when his vehicle hit a tree in the 4200 block of Middlefield Road. His name has not been released.
According to police, the vehicle was northbound on Middlefield Road approaching the intersection at San Antonio Road when it drifted into the southbound lanes, then crossed the sidewalk, where it finally struck a tree.
Police believe the man suffered a medical emergency.
The accident was reported just after 8 a.m. Middlefield was closed for more than five hours as police conducted an accident reconstruction.The victim's name has not been released.
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