DENVER -- A tornado warning covered parts of Adams, Denver, and Weld Counties was allowed to expire at 6:30 p.m. Thursday with no reports of a tornado touching down and causing damage.

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At 5:40 p.m. MDT, National Weather Service doppler radar indicated a thunderstorm with a possible tornado over north central Denver International Airport, or about 19 miles northeast of Denver, moving northeast at 20 mph.

An advisory was issued over the public address system at DIA, but traffic continued without interuption. A DIA media representative denied a report that the terminal was ordered evacuated.

Chuck Cannon said the tornado warning was announced to all passengers, and they were told to stay away from windows, but the terminal was not evacuated.

Cannon said the erroneous report of a DIA terminal evaucation by a local scanner monitoring service prompted a flood of calls to his office by the media. He said at no time was the terminal evacuated.

As the severe weather cell moved northeast from DIA, lightning may have touched off an oil field fire in Keensburg, which was also under the tornado warning. Thick plumes of black smoke rose from near the oil storage facility and fire crews were trying to contain the blaze Thursday evening.

Tornado Safety Tips

If you are caught outside, seek shelter in a nearby reinforced building. As a last resort, seek shelter in a culvert, ditch or low spot and cover your head with your hands.

The safest place to be during a tornado is in a basement. Get under a workbench or other piece of sturdy furniture. If no basement is available, seek shelter on the lowest floor of the building in an interior hallway or room such as a closet. Use blankets or pillows to cover your body and always stay away from windows.

If in mobile homes or vehicles, evacuate them and get inside a substantial shelter. If no shelter is available, lie flat in the nearest ditch or other low spot and cover your head with your hands.