Emergency operations officials in Allegheny County and Pittsburgh hadn't trained for what happened Sept. 11. Never in our wildest dreams did it ever come to the table that they would be using passenger aircraft as missiles," said Bob Full, chief of emergency operations for Allegheny County. It is clear from 911 tapes that local officials had less than 15 minutes' warning that the hijacked United Airlines Flight 93 was in Pittsburgh airspace before the plane crashed at 10:06 a.m. in Somerset County, killing all 44 people aboard. Full learned about the errant plane at 9:53 a.m. That's when he got a call alerting him that the control tower at Pittsburgh International Airport had been evacuated. Thirteen minutes earlier, he had talked to an airport official who had no indication of any threat. Between those two conversations, the Pittsburgh tower had received a call from the Cleveland air traffic control tower, saying a plane was heading toward Pittsburgh and refusing to communicate with controllers. The FAA ordered the Pittsburgh control tower evacuated at 9:49 a.m.