Authorities said a 51-year-old San Diego man was fatally struck Saturday by an Amtrak train in Clairemont in what appeared to be a suicide.

James Robert Schroeder died on the tracks near 5555 Santa Fe St. about 1:05 p.m. Saturday, according to sheriff's deputies and the Medical Examiner's Office.

A northbound Amtrak train was rounding a curve when the engineer saw a man sitting on the east side of the tracks in a no-trespassing area, according to a sheriff's deputy who declined to give his or her full name.

The engineer sounded the horn to warn the man, who stood up and faced the train, the deputy said.

The engineer made an emergency stop but could not avoid hitting the man, who was declared dead on the spot, the deputy said.