LAS VEGAS -- A fire began Monday evening on the 20th floor of Bally’s hotel and casino at 3645 Las Vegas Blvd. South, according to Clark County Fire Department spokesman Scott Allison.

Allison said a motor in an air conditioning unit overheated and sparked a smoky fire, which was contained to an employee lounge area.

He said officials called a second alarm as the first firefighters arrived at the fire at 5 p.m. Monday.

Firefighters were preparing to order everyone out of adjoining floors when the fire was declared out, and the evacuation was called off.

Allison said damage was confined to the air conditioner.

The hotel’s ventilation system cleared the smoke, which took about 30 minutes.

No injuries were reported.