FORT PIERCE, Fla. (AP) — Someone set fire to the mosque once attended by Omar Mateen, the man who opened fire at an Orlando nightclub in the deadliest mass shooting in modern U.S. history, authorities said Monday. No one was injured.

It happened a day after Americans commemorated the 15th anniversary of the Sept. 11 terror attacks, and also coincided with the beginning of the Muslim holiday Eid al-Adha. However, Maj. David Thompson of the St. Lucie County Sheriff’s Office declined to speculate on whether the arson was tied to 9/11 anniversary.

The sheriff’s office said on its official Facebook page that surveillance video shows someone approaching the Islamic Center of Fort Pierce around 12:30 a.m. Monday, moments before a flash was seen and the fire started. The fire was put out, but there was no word on how much damage it caused.

Later Monday morning, a hole could be seen in the roof, with burned wood underneath and soot on some of the eaves. Outside, however, the structure appeared intact.

About 30 investigators were still at the mosque after 9 a.m. The mosque is on a fairly busy two-lane road in a mostly residential neighborhood. Two doors down, the Midway Road Baptist Church has a sign out front advertising a Sunday morning biker chapel and a Korean service.

Multiple agencies, including the State Fire Marshal’s Office, the federal Bureau of Alcohol, Tobacco, Firearms and Explosives and the FBI, are investigating. Sheriff’s officials said they will be releasing the video and asking for the public’s help in identifying the person who set the fire.

Mateen opened fire at the Pulse nightclub June 12 in a rampage that left 49 people dead and 53 wounded. His father is among roughly 100 people who attend the mosque.

Ariana Borras stopped by the mosque with her 2-year-old son Elijah to pay respects Monday morning. Borras said she’s Hispanic and not a Muslim, but because of the color of her skin has been asked if she’s Muslim. She said the fire “makes me scared for my son. It makes me scared for my skin color. There have been a lot of racial issues going on and there’s so much hate in the world right now.”

Michael Parsons, 22, was standing outside his parents’ home Monday, directly across the street from the mosque. He noted that since the Orlando shooting, “a lot of people have been driving by hollering and yelling expletives at the church or mosque or whatever they call it.”

Parsons, a gutter installer with the phrase “trust no one” tattooed on his chest, said his mother’s oncologist attends the mosque. “America was founded so people can believe what they want to believe and do what they want to do,” he said. “These guys flying the American flag on their trucks don’t really know what the freedom is they’re fighting for.”

Officials say the mosque has had other trouble since the Orlando attack.On July 2, a few weeks after the nightclub shooting, a man was beaten outside the mosque, according to Sheriff Ken J. Mascara. The Council on American-Islamic Relations said the victim was a Muslim and said racial slurs were made by the attacker. A suspect was stopped by deputies and arrested a short time later.

The Council on American-Islamic Relations said in a statement that a man in a truck had stopped outside the mosque earlier that same day and made slurs, including, “you Muslims need to get back to your country.”