SAN JOSE, Calif. (KRON) — A San Jose fire captain is mourning the deaths of his three children after they were tragically killed in a grisly crash on Highway 156 in San Benito County, according to a GoFundMe post apparently set up by his colleagues.

Fire Captain Steve Biakanja’s children were students at Carmel Middle School and lived in Carmel Valley. His twin 14-year-old daughters, Leigh and Lucy, and 12-year-old son, Ben, were killed inside a Tesla sedan after it collided with a big-rig truck on August 14, according to school district and law enforcement officials.

According to the California Highway Patrol, the children’s 55-year-old mother was driving the Tesla eastbound on Highway 156 near Fairview Road when she suddenly made a “left turning movement” crossing over double yellow lines.

The Tesla turned into the direct path of an oncoming Freightliner truck, the CHP said.

The four family members were pronounced dead at the scene. The mother’s name has not yet been released by law enforcement officials. The Carmel Unified School District identified the three children and offered grief counselors for students.

“In the wake of great tragedy, San Jose Fire Station 16 is asking for your support to raise funds for Captain Steve Biakanja as he navigates a new reality following the recent deaths of all three of his children in a terrible auto accident,” wrote a GoFundMe page that appears to be set up by fellow firefighters.

“Leigh was a Sea Cadet who enjoyed learning about science and playing softball. Her twin sister, Lucy, loved animals, raising chickens and doves as a hobby. Their younger brother, Ben, leaves behind his collection of World War II memorabilia,” the page states.

The fund had raised $136,000 by Thursday evening. Investigators are still trying to determine why the Tesla crossed into oncoming highway traffic.