Miami-Dade police Lt. Rosanna Cordero-Stutz says the second person died at a hospital on Saturday morning. Three others were taken to a hospital in critical condition.
Officials say the bus was carrying 32 people when it crashed into the overpass. Airport spokesman Greg Chin says the bus was too high to pass beneath the 8-foot-6-inch overhang at the arrivals area.
He says buses and other large vehicles are supposed to go through the departures area, which has a higher clearance.
Cordero-Stutz says the driver, who is being interviewed by investigators, was not familiar with the area and did not intend to wind up at the airport.