After working a late-night shift Friday at an Arlington Applebee's restaurant, Penny Cliatt called her boyfriend to say she was on her way to Saginaw. There, she would spend the night with her boyfriend's family and her 4-year-old son.

Ms. Cliatt, 22 years old and six months pregnant, drove only a few miles before the trip ended.

Police said a drunken driver speeding in an SUV ran a red light and collided with Ms. Cliatt's Toyota Corolla at the intersection of South Cooper Street and Sublett Road in Arlington just before midnight.

As Ms. Cliatt was being transported to John Peter Smith Hospital in Fort Worth, her boyfriend, Travis Smith, was beginning to worry because so much time had passed since her phone call.

"He called me about 1:20 a.m. and said that she called about an hour or two before and said that she was on her way," said Thomas Chapman, Ms. Cliatt's father.

Mr. Chapman hadn't heard from her either, so Mr. Smith began calling area hospitals. He soon learned that Ms. Cliatt was at John Peter Smith, where she and their unborn child were pronounced dead.

The driver of the SUV, 26-year-old Lorenzo I. Carreon of Arlington, was taken to Arlington Memorial Hospital, where he was in intensive care, according to a news release. He will face a charge of intoxication manslaughter, Arlington police Lt. Blake Miller said.

Mr. Chapman said that his daughter, who lived in Arlington, often worked long hours as a server at Applebee's. She was looking forward to a career in either forensics or restaurant management.

"She was more concerned with raising her own children than her career," he said. "She was always kind and a very generous person."

Mr. Chapman said that when Kaleb, Ms. Cliatt's 4-year-old son from a previous marriage, returned from Saginaw on Saturday, he entered his mom's house and asked to see her.

"He hasn't really grasped that she won't be coming home anymore," he said. "He's at such an age that it may be awhile."