The malfunction shut down the airport for about an hour Wednesday evening, and some 15 flights were diverted to either the Fort Collins/Loveland or Colorado Springs airports.
Diverted passengers were allowed to get off the plane, but weren't allowed to take their checked luggage with them.
The problem was probably mechanical and foul play was not suspected, Federal Aviation Administration spokesman Allen Kenitzer said.
Several commercial and commuter airplanes idled on the taxiway, while officials worked on the problem, which was reported in the Terminal Radar Approach Control Facility at the south end of the airport.
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