Capt. Dave Bursten of Indiana State Police said a semi was hauling equipment used to compact cars when that machine experienced a mechanical issue that caused its hydraulic piston to activate and rise on its own. When the semi and its elevated load reached the I-465 overpass, the compactor struck the bridge, he said.
The impact damaged four of the bridge's concrete beams, and left concrete chunks as big as basketballs — and larger — strewn about the highway. Exposed reinforcing steel dangled beneath the damaged span.
The bridge's eastbound lanes also sustained severe damage, INDOT said.
A total of six vehicles were damaged in the impact, including the semi, a utility truck and four passenger cars.
Bursten said one woman was hospitalized in good condition after concrete fell onto her car. The semi's driver was not hurt, and there were no other reported injuries.
"We're very, very fortunate that only one person was injured," Bursten told The Indianapolis Star.