A United Parcel Service cargo plane made a tense landing early Tuesday morning after one of its two engines appeared to malfunction, authorities say.

Jeremy McCulley, operations supervisor at Salt Lake International Airport, confirmed the UPS Airbus A-300 jet came in on an "alert" status about 4:50 a.m. Airport fire trucks were standing by as the aircraft, carrying a crew of two and a load of parcels, landed safely and without further incident.

The plane, UPS Flight 844, had taken off earlier Tuesday morning from Louisville, Ky. Salt Lake City was its scheduled destination.

As of 7:30 a.m., the aircraft was parked on the airport's north cargo ramp. What caused the engine-related malfunction was yet to be determined.

Mike Mangeot, a spokesman for UPS in Atlanta, said that, "As a matter of precautionary procedure, the crew did declare an emergency near Salt Lake City when they couldn't get an indicator light to turn off related to one of the engines."

He added that the aircraft would be "thoroughly examined by our maintenance people in Salt Lake City and appropriate repairs will be made. [Whenever] it is deemed airworthy, it will return to service."