Within a little more than one hour, two people were struck and killed by trains in Palo Alto and Menlo Park.
A man died at Palo Alto's California Avenue station; the second person, a woman, was struck and killed just north of the Menlo Park station.
Their deaths were preceded by a third man, who was struck and killed by an Amtrak train in Fremont.
Gary Carter, 47, of Fremont, was killed by Amtrak train number 727, a westbound Capitol Corridor train, around 10:20 a.m., Danelle Hunter, an Amtrak spokeswoman said.
At about 11:10 a.m., northbound train No. 801, a Baby Bullet express train, hit an unidentified man at the California Avenue Caltrain station in Palo Alto, spokeswoman Christine Dunn said.
At 12:13 p.m., southbound train No. 428 struck and killed a woman on the tracks just north of the Menlo Park station, she said.
The victim in the Menlo Park incident has been identified as Jayne Cox, 27, of Folsom, according to the San Mateo County Coroner's Office.
The identity of the Palo Alto victim has not yet been released, according to the Santa Clara County Medical Examiner's Office.
There have been 16 fatalities on the Caltrain right of way this year, Ms. Dunn said. The highest number of deaths in one year in the Caltrain right of way — 20 — occurred in 1995, she said.