A vacant house on the south side was intentionally set on fire Saturday night.

Multiple people called 911 to report the fire just before 7 p.m. The fire started in an enclosed porch of a boarded up house in the 900 block of East Holladay Street near South Park Avenue and East Drexel Road. Crews were able to extinguish the blaze before it could get to the main house, said Capt. Jeff Langejans, a spokesman for the Tucson Fire Department.

It took nine units and 22 firefighters 11 minutes to bring this fire under control.

“Investigators determined that this fire was incendiary in nature, meaning that the fire was intentionally set by someone,” Langejans said.

Damage was estimated at $20,000.

Langejans encourages neighbors to keep a look out for suspicious activity and report it to 911 or 88-CRIME.

“Even the smallest tip could lead to an arrest and possibly prevent a crime like this from happening again,” he said.