The crash killed a 60-year-old woman and a 29-year-old woman, who was 24 weeks pregnant.
Thirty-year-old Jerell Owens was convicted in the February 2007 fatal shooting of Damian Hopkins.
Engineers who looked into the issue determined the bolt that fell, along with seven others, were not tightened properly.
Head coach Chuck Pagano said Friday that Luck was “questionable” for Sunday’s game.
Authorities described the subject as a male with a square military style hat and a backpack.
Police were still looking for a person of interest, but didn’t believe the crime was random.
It happened in the 1200 block of Villa Avenue.
At least 10 people were killed and seven others were injured in the shooting.