The Florida mosque attended by Omar Mateen, who killed 49 innocent people in an Orlando gay nightclub this summer, was damaged in an arson fire early Monday morning. Flames were discovered shooting out of the Islamic Center of Fort Pierce at about 12:30 a.m., the Orlando Sentinel reports. Officials said video evidence reportedly showed a suspect entering the facility and then setting it ablaze. State fire marshals are investigating the incident. The mosque had reported received threats in the aftermath of the Pulse massacre, and security had been tightened. According to reports, no one was injured.