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.