The wreckage of Air Canada Express Flight 8646, which collided with a fire truck at New York's LaGuardia airport, remains visible to passengers taking off and landing. The National Transportation Safety Board (NTSB) is investigating the cause of the accident, which involved two pilots, Antoine Forest, and Mackenzie Gunther, who died in the collision. The NTSB chair, Jennifer Homendy, said Runway 4 may remain closed for days as investigators sift through a "tremendous amount of debris". The accident occurred late Sunday night and resulted in hundreds of flights cancelled due to a partial government shut down that has led to staff shortages.