The disturbance, which raftled windows, triggered numerous calls to the city police department and the county sheriff's office.
The reverberation, compared by several observers as the sound of a train or hovering helicopters, may well have come from the Defiance General Motors Powertrain plant.
GMPT plant manager Mike Hamilton, who also noted the unusual noise at his home, said this morning he is actively investigating any possible connection vath the foundry.
"We are looking at the timing of the reverberation and trying to tie that back into activity at the plant," said Hamilton. "The timing was similar to the startup of our number 4 cupola, but the disturbance was nothing that we could detect inside the plant."
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The Crescent-News, Defiance, Ohio: Thursday, December 21, 1995
"The noise and vibration correlated to the startup of our number 4 cupola," stated Rick Sufton, director of engineering at Defiance GMPT.
"The most likely cause was combustion system noise on that unit's burner system," said Sutton. "That is a 50 million BTU/hour unit, which is the equivalent of 500-plus home furnaces. Our engineering/maintenance investigation uncovered a malfunctioning valve in that unit which may have caused the problem.
"The valve has been repaired and re-cailibrated, and since then has been running without a problem," added Sutton.
The next time the number 4 cupola will be restarted following the holiday shutdown will be the evening of Jan 1.
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Regarding the "solution" of this phenomena: I know of a former GM employee who lives five miles from GM plant, and he felt this "rumble." He doubts a "faulty valve at GM" was the cause. Even if it were the cause, why was it not heard and felt in the plant itself? -- JLH