The mechanical arm of an excavator that struck a footbridge over the Baltimore Beltway, causing a fatal accident two days ago, was extended at least three feet higher than permitted because the equipment had been loaded backwards onto the flatbed truck, state authorities said yesterday.

The top of the arm was more than 17 feet above the highway -- a foot higher than the maximum clearance for the bridge and three feet higher than the height specified in a state transport permit.

A day after the span plummeted onto evening rush hour traffic southwest of Baltimore, killing the driver of a sport utility vehicle and injuring five people, state police completed questioning the truck driver, Paul McIntosh, 23, of Ontario, Canada. No charges have been filed. Baltimore County prosecutors said they still could bring a case against him.

Police said they were investigating whether he had been behind the wheel longer than legally allowed and whether he had altered his log to cover up his long hours. Federal law mandates eight hours of rest after no more than 10 hours on the road.

"There is a chance that the logs were falsified," said state police Col. David Mitchell. "He could have been driving for too long." Police said investigators became suspicious when McIntosh's account of his activities before the accident did not jibe with the logs.

Police were also examining how McIntosh had improperly loaded the Caterpillar excavator when he picked it up at the South Locust Point docks in the Port of Baltimore. He was transporting it to London, Ontario. Police said yesterday that the shocks on the truck McIntosh was driving were "inoperative."

Tom Simmers, the vice president of International Terminal Operating Co., which leases space at South Locust Point, declined several requests for comment. The trucking company, TTK Transport Inc. of Goderich, Ontario, also refused to comment.

State highway officials reported that in addition to sitting too high on the truck, the excavator was several inches wider than permitted and 400 pounds overweight. Police said the driver was responsible for ensuring that his load met all requirements.

Canadian safety records for TTK Transport were not available yesterday, but figures maintained by the U.S. Department of Transportation showed that since 1997, the company's trucks had failed one of four inspections and been involved in one non-fatal crash.

By morning rush hour yesterday, crews had cleared the bridge rubble from the Beltway, allowing motorists to resume their normal commutes. Valerie Burnette Edgar, spokeswoman for the State Highway Administration, repeated yesterday that the bridge itself had been structurally sound, receiving good marks during its last inspection in early May.

Three of the victims of the bridge collapse remained hospitalized at Maryland Shock Trauma Center, one in critical condition. Regina Brehan, 51, who had been riding beside Robert Norman Taylor, 54, in the Dodge Durango, when he was killed, was in serious condition with a perforated lung, according to hospital officials.

Henri Patrice Williams, 28, initially identified by police by her maiden name McQueen, also was listed in serious condition after surgery to put a steel rod in her fractured femur. Thomas Scalea, head of emergency medicine, said she is responding well to therapy.

When her red Toyota Corolla smashed into the fallen span seconds after the collapse, Williams was heading home from her job as an accountant for the University of Maryland at College Park, according to family members. She had been living with her husband's family in Westminster, and her husband had been caring for their baby while they prepared for a move to Detroit.

"Her husband had just finished medical school and was going to start an internship in Detroit," said Henrietta McQueen, Williams's mother. "Now they have this to deal with. Thank God the baby was not in the car."

Most seriously injured among the three hospitalized victims was Elizabeth Freeman, 68, who was in critical condition on a respirator with multiple fractures and stress to her heart, lungs and kidney, a hospital spokesman said.

When Freeman was late coming home Tuesday to their retirement community, her husband, James Freeman, 84, figured she had been caught in the horrendous traffic tie-ups caused by the fallen bridge. He had seen reports of the traffic jam on the televison. He had switched on the evening news to pass time until she came home to eat dinner with him in community's group dining room.

"I saw it on TV. I even saw that one of the cars was white, but it never occurred to me it could have been our white car," he said. He didn't realize she had been injured until his son called.

Freeman said his wife had been returning home from a visit to their daughter and five grandchildren in Bel Air. She routinely drove there at least once a week to visit and help take care of the younger children, he said. He noted that when her Nissan Maxima collided with the collapsed span, she was just yards from the Wilkens Avenue exit that leads to their Charlestown Retirement Community.

"She was home," he said.

Staff writer Raja Mishra contributed to this report.