The threat of an explosion shut down the Des Moines airport for 90 minuteslate this morning. The threat wasn’t from a bomb — it was from a lowpressure gas line which had been cut by a construction crew. AirportMarketing director Michael Audino (Aw-dean-oh) says the accident happenedaround 10:45 A-M. Passengers were allowed back into the airport terminal atapproximately 12:15. Audino says there were no injuries or other problems.He says passengers may experience problems from the delay at their nextstop. Audino says the accident happened as workers were constructing askywalk in front of the airport terminal.