No one is saying how or why it began, but police say they do know that one group of Howard County teenagers called out another to fight.

About 20 teens agreed to meet for a midnight brawl behind the football field at Mount Hebron High School in Ellicott City. When they got there late Friday or early Saturday, someone had several baseball bats, police said. Soon, three of the teens would be injured, one fatally.

Robert Brazell, 18, of Ellicott City died Sunday at Maryland Shock Trauma Center after being struck in the head with an aluminum bat, authorities said.Kevin Francis Klink, 18, of Columbia was arrested and accused of wielding the bat that killed him.

Authorities said the fight started just past midnight. One group was made up mostly of current and former Mount Hebron students; the other group was mostly from Hammond High School in Columbia. Klink graduated last year from Oakland Mills High School.

Police arrived at the football field about 12:30 a.m. and found three teenage boys injured. Brazell, the most severely injured, was flown to Shock Trauma in Baltimore. Doctors performed two surgeries to stop massive bleeding of the brain, but he died Sunday.

Brazell's family could not be reached for comment.

Two Hammond High students, Jacob Sams and Evan Tubbs, both 17, of Columbia, were taken by ambulance to Shock Trauma for treatment and released. Neither could be reached for comment.

Witnesses at the scene told police that Klink had wielded an aluminum bat during the fight and had hit someone in the head with it, court papers indicate. Police arranged to meet with Klink late Sunday at an Ellicott City gas station and arrested him. During a police interview, Klink confirmed that he had struck an unarmed teen from behind with a bat, according to charging documents.

Police charged him with first- and second-degree murder, first- and second-degree assault and reckless endangerment. Police said they are still investigating what caused the fight and whether all the teens were fighting.

School officials said Brazell had attended Mount Hebron and was a senior when he withdrew in December. Mount Hebron teachers were given a note to read in class yesterday, telling students about the fight. Students and teachers were struggling to understand what had happened, some teachers said. There was no known rivalry between the schools, they said.

It was the first homicide this year in Howard County, an affluent jurisdiction whose schools have a good reputation and are not known for violence.

"The kids are in a state of shock, and the whole thing seems surreal," said one teacher, who spoke on condition of anonymity because school employees were told not to talk about the fight to reporters. "Things aren't supposed to get carried away like that in Howard."

As an Oakland Mills student, Klink came in second last year at the Howard wrestling championships in the 189-pound class.

He is being held at the Howard County detention center without bond. A bail review hearing was scheduled for this morning.

Reached by phone yesterday, his father, Paul Klink, said he had not been allowed to see his son where he was being held. "I don't know what exactly happened. I don't know how to navigate this," he said.

Staff writer Daniel de Vise and staff researcher Meg Smith contributed to this report.