A St. Helena Island teenager has drowned in a pond in a Lady's Island subdivision, authorities said this evening.

Authorities identified the victim as Semaj Johnson, 17, of St. Helena Island. Johnson, who ran track for the Eagles, would have been a senior at Beaufort High School this fall.

Witnesses told authorities that four teens were swimming across the pond in the Ardmore Avenue area of Telfair subdivision when Johnson began lagging behind, struggled, then went under. That was at about 3:30 p.m.; the body was recovered shortly after 6 p.m.

The pond is about 150 yards across and 15 feet deep in some areas. One of the four swimmers lived in a house bordering the pond, according to Lee Levesque of the Lady's Island/St. Helena Fire Department. It's unclear where the others were from.

Officials from the Beaufort County Sheriff's Office, the sheriff's dive team, Lady's Island/St. Helena Fire Department, Beaufort County EMS, the S.C. Department of Natural Resources and deputy coroner David Ott were departing the scene at about 6:45 p.m. Johnson will be taken to the Medical University of South Carolina in Charleston for an autopsy, according to Ott.