A man was killed when his car drifted off of Middlefield Road in Palo Alto Monday morning and struck a tree, police said.

David Louis Jefferson, 63, of Palo Alto, died at the scene after his car struck a tree. The crash was reported at about 8:05 a.m. in the 4200 block of Middlefield Road, just south of San Antonio Road.

Police said it appears Jefferson was driving north on Middlefield Road when his car crossed into southbound lanes, went onto the sidewalk and struck a tree.

Jefferson was alone in the car, was pronounced dead at the scene. No other cars were involved and no one else was injured.

Investigators believe it is possible that he suffered a medical emergency just before the crash, police said. The Santa Clara County medical examiner's office will determine the cause of death, but the medical examiner does not release that information.

Traffic was blocked on Middlefield Road while the crash was investigated, and Santa Clara Valley Transit Authority bus line No. 35 was rerouted.

Anyone with information on the crash is asked to call the Police Department's 24-hour dispatch center at 650-329-2413. Those wishing to remain anonymous can call or text 650-383-8984, or email paloalto@tipnow.org.

— Bay City News Service

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