DALLAS (AP) A truck driver and a 20-year-old college student died Wednesday when an 18-wheeler plunged off a freeway ramp near downtown Dallas and landed on a car on the road below, authorities said.

The tractor-trailer rig loaded with pipes lost control on a ramp that curves toward Interstate 35 and fell on the car, said Paul Lara, a spokesman for Dallas-Fire Rescue.

The mangled truck could be seen underneath the I-35 overpass. Pieces of the truck and lead piping were scattered nearby.

Sgt. Gil Cerda, a Dallas police spokesman, said that the trucker's load may have shifted. Police said the truck driver must have taken the turn on the ramp too quickly.

David Simonelli, 38, the truck driver, was pronounced dead at the scene. So was 20-year-old Ashley Parra, who was killed when the truck fell onto her car.

"I've never seen anything like it," Cerda said. "Another vehicle falling on your vehicle as you're traveling is just unbelievable."

Said Dallas police Sgt. Johnnie Harris: "Just a 10th of a second from it not happening to her. She never knew what hit her."

Parra was a student at the University of North Texas. She had attended Southern Methodist University for two years before transferring. She was on her way to work at a downtown restaurant when she was killed, her grandmother said.

"She had good grades, she had a lot of potential and she was going to grow up and be somebody someday, and now she's gone," said Susan Castro, Parra's grandmother.

Simonelli had been working for Texas Land & Air Co. for about a month, said Todd Bennett, the company's chief executive officer.

"My heart and prayers go out to the families involved," Bennett said.

Information from:

The Dallas Morning News: www.dallasnews.com

Copyright 2008 The Associated Press.