A 4-year-old girl was shot and killed during an attempted carjacking in northwest Houston.

Houston police said the attempted carjacking happened about 2 p.m. Sunday.

Investigators said a family of four was in their car when a man approached with a semiautomatic weapon and demanded the keys.

The father told police he first thought it was a joke. He then said to the man, “Let me get my family out of the car.”

Seconds later, shots were fired and the couple’s 4-year-old daughter was fatally wounded, detectives said.

Neighbors saw what happened next.

“I saw her mom grab her and said, ‘Oh, my baby’s shot,’” a witness who did not wish to be identified said. “It’s just my heart goes out to her and, oh my God, I know how she feels. It’s just terrible.”

Police said the suspect left without the car.

The parents tried driving to a hospital and flagged down a deputy along the way at Beltway 8 near Veterans Memorial Drive, but their daughter was pronounced dead.

Investigators said the victim’s 1-year-old brother was also hurt and was transported to Memorial Hermann in the Texas Medical Center. His condition was not released.

Police said a person of interest was questioned Sunday night.

A description of the shooter has not been released.