WFAA-TV

The gravely injured officer is moved to an ambulance.

DALLAS — A Dallas police officer escorting Sen. Hillary Rodham Clinton's entourage to a rally in Oak Cliff Friday morning lost control of his motorcycle and was killed.

Police identified the officer as Senior Cpl. Victor Lozada-Tirado, 49, a 20-year veteran of the department.

The accident happened on the Houston Street viaduct around 9:20 a.m. The Kawasaki 1000 Police Special motorcycle apparently hit a concrete abutment.

HD Chopper 8 pilot Troy Bush, who flew over the scene shortly after the incident, estimated that the officer had been thrown about 20 yards by the impact after apparently hitting a railing.

Cpl. Lozada-Tirado was rushed to nearby Methodist Medical Center, where he was pronounced dead. He had been with the department's traffic division for five years and was also well-known in the East Dallas community for his work at a storefront station on Hall Street.

"The accident is still under investigation, but the motorcycle escorts that we do are very dangerous," said Dallas police Chief David Kunkle. "It is our understanding and belief at this time that it was a single-vehicle accident involving Officer Lozada-Tirado's motorcycle."

Cpl. Lozada-Tirado was married with four children — two boys and two girls.

He had been with the department's motorcycle unit for little over a month. This was his second assignment; he also was part of the motorcade for Sen. Barack Obama when he brought his campaign to Dallas earlier this week.

After learning of the accident following her Oak Cliff rally, Sen. Clinton offered her condolences to the victim's family and to the Dallas Police Department, calling it a "tragic, tragic loss."

Dallas PD

Senior Cpl. Victor Lozada-Tirado.

"We are just heartsick over this loss of life in the line of duty," she said. "This reminds us once again of what our men and women in law enfocement do every single day, and it is imprtant that we respect and appreciate their service. I certainly am grateful for all they do for me, and — more importantly — what they do for the citizens of Dallas."

A somber candidate moved to her next scheduled event in downtown Worth at 11:15 a.m., and spoke briefly to supporters about what had happened in Dallas. Clinton left the rally without delivering a stump speech, and said she was going back to Dallas to the hospital where the officer died.

"His wife, obviously, is devastated by his death," Chief Kunkle told reporters. "It's gut-wrenching to be there with her."

The chief said the officer's wife does have a strong support system.

Last year, a police officer was killed while escorting a motorcade for President George W. Bush in Albuquerque, N.M. There was a similar fatal crash involving a presidential motorcade in Hawaii in 2006.