A 14-year-old girl is facing arson and attempted murder charges after setting her family’s Florida house on fire in what authorities say was an senseless act of violence fueled in part by the teen’s obsession with the fictional horror figure Slender Man.

Authorities in Pasco County say the girl torched the Port Richey home she shared with her mother and 9-year-old brother early Thursday. They say she soaked a towel and a bed sheet with bleach and rum and set it on fire in the garage. The mom and the boy were sleeping at the time. They fled the burning house safely after a smoke detector alarm went off. Firefighters responded to the fire around 1:45 a.m., authorities said.

The Suncoast News said the teen, Lily Marie Hartwell was found several hours later and taken into custody. She attended a local middle school.

The Tampa Bay Times said that according to the arrest report, the girl sent her mother a text: “Mom Im so sorry I don’t know why I did it.” She also asked in another text if anyone got hurt.

Pasco County Sheriff Chris Nocco said Hartwell had been reading an online book called “Soul Eater.” “It’s very disturbing,” he said at a news conference. “It’s about killing people.”

The sheriff said the girl had also been reading about Slender Man and wrote in her journal about two 12-year-old Wisconsin girls who were inspired by the creepy character to stab a classmate 19 times in May.

Nocco said Hartwell also had visited creepypasta.com, where visitors to the website can blog about Slender Man.

“It’s a tragedy,” neighbor Sandy Gilbert told the Suncoast News. “I hate to see something like this happen to such a nice family.”