Separate investigations by the U.S. Occupational Safety & Health Administration and the contractor Kokosing into the cause of the Jan. 19 Interstate 75 overpass collapse near Cincinnati will likely take months. But an industry expert suggests that adequate engineering documentation before the demolition of the overpass might have prevented the accident, in which the middle span fell onto I-75 and killed a worker.

Crews with Kokosing, which holds a $91-million contract to rebuild the Hoppell Interchange, cleared the debris and repaired the highway within 24 hours of the Monday night accident. Kokosing had been removing the overpass span by span.