mark goldstein, a former air traffic controller and contract pilot. the plane had just come out of a major inspection and altitude testing. goldstein was flying the plane to arkansas to be painted. this is the audio from air traffic control. you hear the pilot say prepare for an emergency. just lost the left engine. reporter: and then we just lost an aircraft. reporter: there were approximately 100 people in the building at the time of the crash. ryan peterman is an instructor who was in a safety class. the building kind of shook and rumbled. when we saw the smoke plume cast a shadow, we knew something was wrong. reporter: portions of the building sustained significant collapse and were unsafe. the ntsb will investigate yesterday s crash. t.j., reena? karen, thank you. another crash in the heartland turned a halloween