PORT RICHEY — A 14-year-old girl immersed in violent Internet fiction and angry at her mother about household chores set fire to her family's house early Thursday, Pasco authorities said.

While her mother and 9-year-old brother slept, the girl soaked a towel and bedsheet with bleach and rum and then lit them on fire in the garage, according to an arrest report.

Later, the report says, she sent her mother a text saying, "Mom Im so sorry I dont know why I did it." She also asked if anyone was hurt.

The girl, whom the Tampa Bay Times is not naming because of her age, was charged with arson and two counts of attempted murder. Investigators say she admitted to starting the fire.

Pasco Sheriff Chris Nocco said in a news conference that the girl had been reading an online book called Soul Eater about killing people. The girl also wrote in her journal about two 12-year-old Wisconsin girls who stabbed and nearly killed a classmate this year — a crime said to have been inspired by the fictional Internet character Slender Man, who terrorizes children in stories. She had also visited creepypasta.com, where people blog about Slender Man.

"There's a clear direction," Nocco said. "She's involved in reading these things."

Yet outwardly, she didn't betray a dark side. She didn't dress in all black, a detective said, and comes from "a good family."

"You wouldn't look at her and think she was following … an extreme Gothic type of role," Detective Daniel Toner said.

The girl's mother told authorities that she woke up to smoke inside the house on Hermitage Lane around 1:45 a.m. She got her son out of bed but couldn't find her daughter. After walking her son outside, she went back in to look for the girl.

When Pasco County firefighters arrived, flames were shooting through the roof. Rescue crews searched the home three times for the girl and found no one inside, officials said. It took 17 firefighters from three stations to squelch the flames.

The girl, a Chasco Middle School student, told investigators she packed a bag with clothes, bottled water, cookies, knives, lighters and flashlights and walked to a nearby park restroom, where she slept.

Before lighting the blaze, Nocco said, she changed out of her loose-fitting pajamas when she realized they could catch fire.

"She planned this whole thing out," he said.

In the journal marked "Keep Out," one entry stated, "If this keeps up there will be no safety in this house."

Jim Colucci, 49, who lives next door, said he was wakened by another neighbor pounding on his door, yelling to get out of the house because of the fire. He said he got his family and dog out and moved his car away from the flames. Then he watched as the flames rolled out of the garage to within steps of his own home. It caused only minor damage to the wall of his home closest to the other house.

"If this was something that was done on purpose," Colucci said before charges against the girl were announced, "then we need to do something as a community."

Investigators have not decided whether to charge the girl as an adult. She was being held at the Pasco Juvenile Assessment Center.

The house was left uninhabitable.