A grand jury declined Monday to indict a bus driver in connection with the deaths of 23 passengers killed in a fire that destroyed the vehicle as they fled Hurricane Rita in September.

The Dallas County Sheriff's Office had forwarded to the district attorney 23 cases of criminally negligent homicide to consider against Juan Robles Gutierrez, 37, a Mexican immigrant.

The bus, owned by Global Limo Inc. caught fire Sept. 23 from a malfunctioning back wheel. After the fire started, oxygen tanks used by some of the patients on the bus began exploding.

The grand jury's decision not to indict Robles would not be a setback for the department's investigation, said Sgt. Don Peritz, a spokesman for the sheriff.

"There are still many aspects of the investigation to look at," he said in a story in Monday's online edition of The Dallas Morning News. "You've got the people that leased the bus, the people that owned the bus, the people that maintained the bus."

The sheriff's department had said Robles did not inspect the bus periodically on the 16-hour trip from the Brighton Gardens nursing home in Houston as Rita approached, and didn't help people when the fire broke out.

But Robles' attorney, George Shaffer told Tuesday's editions of the Houston Chronicle that his client "did everything within his power to minimize the damage and loss of life. He did everything any human would have done."

Carlos Robles Gutierrez said he was glad to hear that his brother was cleared. "We always believed in U.S. justice," he told The News by phone from Monterrey, Mexico.

Officials at the Mexican Consulate in Houston expect Robles to be released on bond by Tuesday. He has been detained as a material witness in the investigation and still faces immigration charges for being in the United States illegally.

"We feel happy for him. We'll keep supporting him until this process ends," Adhemir Olguin, a spokesman for the consulate, said late Monday.