An autopsy today is expected to confirm the identity of the worker killed yesterday at Denver International Airport when he was struck by a giant sweeping vehicle during a runway cleaning operation.

Authorities won't name the man, who worked for subcontractor Rampart Hydro Services, until his identity is confirmed by fingerprinting during before the autospy, an official with the Denver medical examiner's office said this morning.

The office may also make public a preliminary report on the cause of death today.

Federal and local authorities said an investigation into the death will probably take two months to complete. It will look into the mechanics of the scrubbing machine, why the victim was on foot, and visibility, among other things, said Herb Gibson, Denver area director for Occupational Safety and Health Administration.

"We're doing a thorough job, so that it doesn't occur again in the future," Gibson said.

The accident victim, believed to be in his mid-40s, was hit at 5:16 a.m. by the massive orange runway sweeper during a routine maintenance operation on runway 16L/34R, DIA spokesman Chuck Cannon said.

The big sweeper was driven by a DIA maintenance worker who had worked at the airport for a few years, according to Cannon. He was not identified Monday.

Denver Police Detective John White said the worker apparently bent over to pick up an object, and the sweeper operator did not see him.

The subcontractor, Rampart Hydro Services, uses big trucks blasting high-pressure water to strip rubber residue left by landing jetliners from runways.

The runway was closed for the investigation but was reopened shortly before noon Monday. Air traffic wasn't affected because DIA diverted flights to five other runways, Cannon said.

The death comes less than a week after an electrician drove on a DIA runway without authorization.

DIA restricted motor vehicle access to the airfield and increased driver training after that violation.

gathrighta@RockyMountainNews.com or 303-954-5486.