There has been totally five structures, including Cowboys now-ruined facilty, built by Summit to collapse since 2002. The other collapsed structures were a warehouse-type building in upstate New York, an indoor arena for horse competition in Oregon and an aircraft shade covering at the Naval air station in El Centro, Calif.
Philly port official said that Cowboys official Bruce Mays contacted him about warehouse built by Summit collapsing during a snowstorm, before they hired Summit to build their practice facility. So they should have known about other failed canopies by Summit. Since Cowboys still hired Summit, they considered that Summit and Dallas were working cooperatively and fixed problem that may cause collapsing.