Person killed crossing Caltrain tracks in San Mateo

CANTARA4-C-13JUN01-MT-MJM Standard railroad ties were replaced with concrete ties to create a more precise rail platform along with an inner rail system. Ten years ago on July 14, 1991 a Southern Pacific train carrying 19,000 gallons of the highly toxic pesticde Metam Sodium derailed near Dunsmuir, California dumping the pesticide into the river, killing all the fish and plant life in the area. The toxic material made it's way 40 miles downstream to Lake Shasta. Since the spill, Union Pacific Railroad spent $6 million on track improvements in an eight and a half-mile area along the Upper Sacramento River, including the site of the spill. CHRONICLE PHOTO BY MICHAEL MALONEY less CANTARA4-C-13JUN01-MT-MJM Standard railroad ties were replaced with concrete ties to create a more precise rail platform along with an inner rail system. Ten years ago on July 14, 1991 a Southern Pacific train ... more Photo: MICHAEL MALONEY / SFC Photo: MICHAEL MALONEY / SFC Image 1 of / 1 Caption Close Person killed crossing Caltrain tracks in San Mateo 1 / 1 Back to Gallery

A person was struck and killed by a Caltrain near Bellevue Avenue in San Mateo Tuesday afternoon, according to the transportation agency.

The person — whose identity was not immediately available — was allegedly trespassing on the tracks when he or she was struck by a southbound train around 2:30 p.m. Tuesday.

Passengers should expect major delays on the southbound line as authorities investigate the incident.

The fatal train accident was the second in as many days in the Bay Area. A man crossing the Union Pacific railroad tracks on Monday in Albany was struck and killed by an Amtrak train near the Buchanan Street overpass near Interstate 80, fire officials said.

That incident triggered system-wide delays for trains operating on the Capitol Corridor, the passenger rail line between Silicon Valley and Sacramento.

Michael Bodley is a San Francisco Chronicle staff writer. Email: mbodley@sfchronicle.com