CEDAR HILL, Texas - A Dallas firefighter is charged with intoxication manslaughter after a crash that killed a pregnant teen and her unborn child, reports CBS DFW. According the station, an arrest warrant for Horace Shaw III details what witnesses saw before and after the accident in the early morning hours of December 13. 

Witnesses say they saw a white Mercedes Benz traveling at what appeared to be more than 100 mph. Two people were inside the car, a passenger and Shaw, a firefighter who was off-duty at the time.

Witnesses say the car crested a hill and crashed into a Mazda SUV carrying pregnant teen Alyssa Pimental and passenger Isaiah Perez, both of whom were thrown from the vehicle.

At least two people told investigators that Shaw appeared intoxicated and "wasn't able to walk straight" after the crash, according to the station. Officers later found a metal flask, that they say smelled of alcohol, in the car he was driving.

The passenger in the car with Shaw told police the two had just left a restaurant and bar in Duncanville where they had been drinking. The man also said Shaw was showing off and "speeding a little bit" before the crash. Officers said that passenger, who has not been identified, also smelled of alcohol.

Pimental was taken to Charlton Methodist Hospital but both she and her child died.

Shaw was taken to Methodist Central Hospital where he was advised of his rights, declined to answer questions and requested an attorney.

Hours after the crash Perez told CBS DFW that Pimental was the "love of his life" and talked about the baby they were expecting to welcome into the world by Christmas. Perez has a broken leg and a fractured neck but was released from the hospital on Wednesday night.

"I didn't feel it," he recalled. "I just woke up on the ground, like somebody hit you on the back of the head."

Shaw has been with Dallas Fire-Rescue for 12 years, but has been placed on administrative leave. He was booked into the Dallas County Jail but has since been released on bail.