A 7-month-old girl was struck and killed by a vehicle reportedly driven by her mother in Ontario late Monday after an argument between the mom and the child’s father, police said on Tuesday.

“It appears alcohol was involved,” said Sgt. Jeff Higbee of the Ontario Police Department.

It was unclear if the crash was intentional, the sergeant said.

The child was in her father’s arms when the mother, 19-year-old Sarah Marie Gomez, allegedly struck them after an argument just before midnight outside a home on the 500 block of West D Street, Ontario police said.

The couple had been at a family member’s home for a gathering earlier in the day and had come home, and were arguing in the vehicle, Higbee said.

“He got out of the car with the baby, and that’s when she struck them,” Higbee said. “But we’re not certain yet how that happened. That’s still under investigation.”

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A family members took the father and child to a hospital, where the baby died. The father sustained minor injuries.

Gomez was initially arrested on suspicion of assault with a deadly weapon but that was later changed to suspicion of murder and attempted murder, according to police.

It wasn’t immediately clear what sparked the argument.