COMMERCE CITY, Colo. -- Two suspects are in custody following a shooting that killed one teen and injured another at Fairfax Park in Commerce City.

The shooting victim was identified by authorities as Benny Williams, 15, a student at nearby Adams City High School. Williams was shot once and died at the scene.

His brother, Rodney Williams, 16, was shot three times and was rushed into surgery at Denver Health Medical Center. His condition was not known but he was expected to survive, police said.

The shooting occurred around 12:45 p.m. near 68th and Fairfax. The body of the victim was not removed from the park until after 4 p.m. Several city park workers reportedly witnessed what happened and were being questioned by police.

Other witnesses said the gunfire was preceded by a loud argument between a group of teens.

One woman who reached Benny Williams said he died shortly after the shooting.

"I was on the phone (calling 911) and I was trying to help him. He was alive and not breathing well and he just died while I was sitting right there," said eyewitness Bonnie Banschoick.

All 11 schools in Adams County District 14 were locked down around 1 p.m. as Commerce City police scoured the area for additional suspects. During a lockdown, no one is allowed to leave or enter the school and parents must show proper identification to pick up their children.

The lockdown was lifted around 3:30 p.m. but students were let out later than usual and buses ran late to accommodate.

The teens who were arrested were apprehended along the railroad tracks in the 6700 block of Highway 2. Investigators are conducting interviews to determine their involvement in the shooting.

The Adams County Sheriff's Office also sent K-9 units to the scene to help in the search for additional suspects. It is not known how many suspects police are searching for and the motive for the shooting remains unclear. A weapon has not been recovered.