Before Omar Mateen shot up the Pulse nightclub in Orlando and killed 49 people in June, he had been a longtime regular at the Islamic Center of Fort Pierce, showing up at Friday services for 13 years. That mosque went up in flames early Monday, per the St. Lucie County Sheriff's Office, and officials are investigating it as an arson case, CNN reports. Per CBS News, a statement from the sheriff's office says surveillance video at the mosque shows a person approaching the building "just moments before a flash is seen and the fire starts." Mosque leaders say they'd been receiving threats—including those that said the mosque would be set ablaze—since the shootings, WPEC reported in June.
What made the mosque notable, in addition to it being Mateen's place of worship, is that Moner Mohammad Abu-Salha, believed to be the first American suicide bomber in Syria, also attended services there. But another attendee told CNN in June that there was nothing unusual about the mosque and that "we never hear any stupid things coming out from anybody. It's very low-key." As for the link to both Mateen and Abu-Salha, he notes, "It's very strange to me." (Read more Pulse Orlando shooting stories.)