ATLANTA - What was shaping up to be one of the busiest travel days ever at the world’s busiest airport hit a snag late Friday afternoon after the air traffic control tower was evacuated.

What we know:

According to the FAA, the tower at Hartsfield-Jackson Atlanta International Airport was evacuated around 5 p.m. after a fire alarm and reports of a strong natural gas odor.

A ground stop was initially issued for all inbound flights through 6:15 p.m. but was lifted about 45 minutes later.

An FAA official told FOX 5’s Tyler Fingert that Atlanta Fire Rescue responded to investigate.

No injuries have been reported.

According to FlightAware.com, flight delays jumped from just over 280 to 360 during that time span. That total grew again to 500 flights by 7 p.m.

Nine flights were canceled f

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