A Christmas tree fire caused heavy damage to a home on Tucson's south side Dect. 27, 2017.

Tucson firefighters responded to multiple 911 calls reporting a Christmas tree on fire inside a south-side home Wednesday night, authorities said.

Shortly after 8 p.m., firefighters arrived at a house in the 300 block of West Pennsylvania Drive and saw smoke coming from the eaves, and smoke and flames in the front room of the house, said Capt. Andy Skaggs, a Tucson Fire Department spokesman.

Firefighters forced their way into the house and the fire was put out in 21 minutes, said Skaggs. It took 24 firefighters to bring the blaze under control.

The fire was contained to the front of the house, but heavy smoke caused damage throughout the house, Skaggs said.  

He said it appears the Christmas tree was the first item to ignite. Investigators were working to determine the cause of the fire. A damage estimate had not been determined. 

No one was home during the fire. A woman and her son were displaced by the blaze.

Skaggs said Christmas trees are the leading cause of fires at homes during the holiday season. He said these fires can be avoided by disposing of trees soon after Christmas.

Contact Star reporter Shaq Davis at 573-4218 or sdavis@tucson.com

On Twitter: @ShaqDavis1