Two years ago, when David Evans arrived in Lake Placid, N.Y.—site of the 1980 Winter Olympics—the field house for the Games was little more than a gaping hole and a blueprint. As a U.S. government engineer sent in to help monitor the Commerce Department's $47 million investment in the Lake Placid facilities, Evans was "proud and excited to be part of the Olympics." But then construction started, and each daily inspection provoked some fresh alarm. There were faulty welds, he charges; steel columns out of plumb, sagging beams, missing braces, concrete left to freeze before it could harden. "Every time I showed up there was something else," Evans recalls. Concluding finally that the steel trusses supporting the roof of the 8,500-seat arena could be unsound, Evans made the point so emphatically that he was banned from the site by his bosses.

Two weeks ago an unfinished stadium collapsed outside Chicago, with five workers found dead in the rubble. It was the fourth cave-in of a large public arena within two years. Suddenly Evans' alarmism seemed grimly vindicated. "The construction industry is totally messed up," he says, "and we're not learning from our mistakes. Nobody died in the first three disasters, and, human nature being what it is, we probably won't learn our lesson until a lot more lives are taken."

A former executive director of the New York State Society of Professional Engineers, Evans sees the Lake Placid controversy as the microcosm of a nationwide problem. "There's faulty design, shoddy construction and hanky-panky everywhere," he claims. He finds too little pressure for safety—and too much to finish construction on schedule. "We've tried to walk a proper line," argues a high Commerce Department official. "Evans has been on the side of safety at any cost, and we think that's one-sided." Still, he believes Evans is sincere, and concedes: "I only have to read a newspaper or even look at my own house to know something is going wrong."

As a corrective, Evans proposes replacing the maze of local construction rules with "a national building code with the full weight of the federal government behind it." Further, he suggests that the National Bureau of Standards be called in to regulate construction practices. "I'm no fan of creating new bureaucracies," he says, "but this agency is already there."

Born in Pittsburgh, Evans, 42, learned about construction from his father, a U.S. Steel executive. In high school, David was an Eagle Scout and a political conservative. After graduating Duke with a B.S. in engineering, he went to work for U.S. Steel, but a reform instinct led him to full-time work in professional societies—and to become an unofficial gadfly on construction jobs from Manhattan to Guam.

None of them was quite as hairy for him as the Lake Placid imbroglio. In the wake of his allegations last fall, he was warned that his life had been threatened, and his civil service job, he believes, was saved only by "whistle-blower" laws which protect government employees against dismissal for exposing a situation which management should have reported (he is still appealing his job restriction).

An official of Gilbane Building Co., which is managing construction of the Lake Placid project, insists that "most of Evans' charges are unfounded." But last week a five-month investigation commissioned by the Olympic committee concluded that some of the defects he pinpointed are already being fixed—and that several others should be monitored. How many would have been caught without Evans is anyone's guess—and moot besides. "I plan to stay around until the job is done," he says, ban or not. "This building is going to be safe." As for others, Evans is less reassuring. "It's a sure bet," he warns, "that there will be more collapses."