Mom and 2 Daughters Killed in Mother's Day Crash on Calif. Freeway: 'It's Heart-Wrenching'

"This was a traumatic scene with injuries of young people and a mother on Mother's Day," one official said

A mother and two girls died after a crash on Mother's Day, according to California authorities.

The two-car crash occurred around 7:30 a.m. local time on Interstate 10 in the Whitewater area, according to The Palm Springs Desert Sun and ABC affiliate KESQ. At least six of the nine people inside the car, whom officials say were all members of the same family, were ejected or partially ejected from the vehicle, reported NBC and The CW affiliate KTIV.

Relatives told NBC Los Angeles that the family was on the freeway heading to the Palm Springs area for a celebration, the station reported.

"This was a traumatic scene with injuries of young people and a mother on Mother's Day, and it's heart-wrenching," California Highway Patrol Officer Jason Montez told reporters on the scene, per KTIV.

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California Highway Patrol (CHP) said a black Tesla Model 3 and red Chevrolet Suburban collided for reasons that are still unknown, leading the Chevrolet to crash into a center barrier, per the outlets.

Three individuals — 31-year-old Cecilia Villalobos and two girls, ages 12 and 8 — were pronounced dead at the scene, per KTIV and NBC Los Angeles.

A family member identified the girls as Villalobos' daughters, according to NBC Los Angeles. A vigil was held for them on Monday.

Six other people were injured in the crash. Four of the injured — ages 3, 7 and 11 and 15 — suffered major injuries, Montez said, per KESQ.

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Two of the seriously-injured minors were airlifted from the scene and transported to a local trauma center, the The Palm Springs Desert Sun reported. The 15-year-old boy was transported to the hospital via ambulance.

A 39-year-old man, who was driving the Chevrolet, suffered moderate injuries in the crash, per the Sun and KESQ. A 41-year-old passenger suffered minor injuries, as well. Meanwhile, the driver of the Tesla was uninjured.

CHP did not immediately respond to PEOPLE's request for comment.

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Some of the individuals traveling in the Chevrolet were not buckled into their seats, CHP said, according to KESQ. Additionally, Montez said the suburban was only built to carry eight people, per KTLA.

"The California Highway Patrol would like to remind you to only drive a vehicle with a safety belt/child safety seat for every occupant and always buckle up,'' Montez said, per the report.

The cause of Sunday's crash remains unknown. An investigation is ongoing.

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