(CNN) -- Several hundred tons of concrete fell from an overpass and crashed onto Interstate 75 in Cincinnati, killing a construction worker.
The “catastrophic pancake collapse” occurred Monday night as workers were preparing for the demolition of the overpass, the Cincinnati Fire Department said.
A semi truck driver struck the debris on southbound I-75 and suffered minor injuries, City Manager Harry Black said.
Cincinnati Police Chief Jeffrey Blackwell said the driver was extremely lucky.
“A matter of seconds, and his fate would have probably been different.”
A stretch of southbound I-75 will be closed at least through Wednesday, Blackwell said, as crews try to clear the enormous debris.
At the same time, officials will try to determine what went wrong.
“Who knows what happened,” Black said. “But we will find out.”
CNN’s Jennifer Moore contributed to this report.
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