Flagstaff, AZ - Five passengers were injured Sunday when their flight to Phoenix made an emergency landing in Flagstaff. At 10:30 a.m. the Allegiant Airlines flight from Billings, Montana diverted to Flagstaff Pulliam Airport when an indicator light suggested there was a fire in one of the MD-83 engines. Ian Gregor, the Federal Aviation Administration spokesman, announced that it was not clear whether or not the engine actually contained a fire. It may be possible that the indicator light was activated by a false sensor.