Boston ? Seven years before falling concrete crushed a motorist to death inside one of Boston’s Big Dig tunnels, a safety officer warned that the bolts could not possibly hold the heavy ceiling panels, according to a bluntly worded memo leaked to a newspaper.

John Keaveney wrote the memo in 1999 to one of his superiors at contractor Modern Continental Construction Co., saying he could not “comprehend how this structure can withhold the test of time.”

“Should any innocent State Worker or member of the Public be seriously injured or even worse killed as a result, I feel that this would be something that would reflect Mentally and Emotionally upon me, and all who are trying to construct a quality Project,” he wrote, according to a story Wednesday in The Boston Globe, whose reporter was mailed a copy of the memo.

Since the accident July 10, other documents have come out showing that there were questions over the years about the reliability of the ceiling bolts. But Keaveney’s memo is one of the bluntest and most emotional warnings to come to light. And Keaveney was the safety officer directly responsible for the tunnel where the accident took place.

Gov. Mitt Romney said that the disclosure “really made me feel a little ill,” and he questioned why it had not triggered aggressive inspections. “You shake your head and say, ‘Gosh, why didn’t anybody go in there, particularly knowing the kind of information that was in those memos in the past?”‘ he said.

He said inspections since the July 10 accident in which panels fell and killed 39-year-old Milena Del Valle in her car have revealed problems throughout the $14.6 billion project, the most expensive highway project in U.S. history.

Investigators have been focusing their attention on the bolt-and-epoxy system holding up the ceiling panels, which weigh about 3 tons each.

In an interview with the Globe, Keaveney said his superiors at Modern Continental and representatives from Big Dig project manager Bechtel/Parsons Brinckerhoff assured him that such a system had been tested and was proven to work.

The superior to whom Keaveney sent the memo, Robert Coutts, senior project manager for Modern Continental, was on vacation and unavailable for comment, a family member told the newspaper.

Massachusetts Atty. Gen. Tom Reilly is conducting a criminal probe of the accident.