FORT LAUDERDALE, Fla. -- Dozens of high school students gathered before classes Thursday for a brief prayer service a day after authorities said one 15-year-old girl shot and killed another in a crowded hallway.

Some students wore black, while others brought flowers and teddy bears to the service next to three flagpoles outside Dillard High School.

Teah Wimberly, a sophomore, is charged with first-degree murder and discharging a weapon on school property in the killing of Amanda Collette. Investigators said Wimberly shot Collette, then walked to a seafood restaurant to call authorities and turn herself in.

The shooting around 11 a.m. Wednesday set off a confused chain of events at the school: Witnesses said students screamed and ran when the victim fell to the floor, but authorities couldn't immediately confirm a shot had been fired.

Stephan Willis, a sophomore, said the girls were arguing in an outside corridor when Wimberly suddenly pulled out a gun and shot Collette.

"She's a nice girl. She's quiet. She just keeps to herself," Willis said of the victim, whom he said he'd known since elementary school.

Police said they did not believe anyone heard gunshots, and an initial examination found no major wound on the girl's body.

Authorities later confirmed the shooting. It was possible a smaller-caliber gun was used and the wound closed around the bullet, said Sgt. Frank Sousa, a spokesman for Fort Lauderdale Police. The school was locked down for a short time, but classes soon resumed.

Wimberly left campus and walked across the street to Captain Crab's Take-Away restaurant where she called authorities and told them "she had shot her friend," Sousa said. Authorities took her into custody at the restaurant and recovered a gun.

Wimberly was being questioned by police Wednesday evening. Messages left with police seeking an attorney for her were not immediately returned.

No other students were believed to have been involved.

Dillard has about 1,700 students. They don't pass through metal detectors, but officers are stationed on campus and security cameras are placed throughout.