PALO ALTO -- A 23-year-old man was struck killed by a passenger train Monday morning, marking the fifth Caltrain fatality of the year.

The Palo Alto resident was hit by a train traveling north in the area of Charleston Road around 6:45 a.m., according to the Santa Clara County Medical Examiner's Office. He was pronounced dead at the scene.

No further information about the man's death was available on Monday and it was not clear why he was on the track. Morning train service was upset for commuters, with passengers initially being rerouted onto buses through the area until the tracks in both directions were back in operation around 8:15 a.m.

Last week, 16-year-old Lincoln High School student Donae James Johnican was killed by a train near Virginia Street in San Jose in what was deemed an accident. In 2012, there were 12 fatalities on Caltrain tracks; eight of those were considered suicides.

Contact Eric Kurhi at 408-920-5852. Follow him at Twitter.com/erickurhi.