A postal worker, a truck driver and a high school student were among the seven people gunned down in a mass shooting in Texas over the weekend, officials and relatives said Sunday.

Twenty-two people, including a 17-month-old girl, were also injured in the rampage, which occurred after a traffic stop between the west Texas cities of Midland and Odessa on Saturday afternoon.

The gunman was killed in a shootout with police near a movie theater after he abandoned his car and stole a U.S. Postal Service van.

The Postal Service identified the dead letter carrier as Mary Granados, 29.

Granados’ twin sister, Rosie Granados, said they had planned to celebrate their 30th birthday together.

“She was so special,” Rosie Granados said. “I don’t know what I’m going to do without her.”

Rodolfo Arco, 56, was also killed in the rampage, according to his wife, Bari Acro.

Bari Arco said the couple has been married for 20 years and have three daughters, ages 3, 6 and 23. The family moved to Odessa from Las Vegas nearly a year ago for Rodolfo Arco’s trucking business.

On Saturday, she said, he was returning from work when a bullet struck him in the head.

“Now he’s gone,” she said.

An Odessa High School student was also killed in the shooting, Ector County Independent School District confirmed Sunday. The student has not yet been identified.

The parents of 17-month-old Anderson Davis said their daughter, whose face and chest were injured by shrapnel, was recovering after undergoing surgery on Sunday morning.

Local police have said it’s unclear why the shooter opened fire Saturday, but they have said the shooting doesn’t appear to have been motivated by domestic or international terrorism.

The gunman had recently been fired from a job, law enforcement officials said.