A 16-year-old boy who went missing while swimming in the Potomac River was found dead Saturday following a 36-hour search.

The Montgomery County Police Search Management Team and the Montgomery County Fire and Rescue Service Swift Water Rescue Team recovered the teen's body at 9:30 p.m. Saturday, according to a Montgomery County Police Department press release. He was pronounced dead at the scene.

The teen had been swimming with a group of friends on Friday near the 10800 block of MacArthur Boulevard when he went under the water and did not resurface. MCFRS Swift Water Rescue units were dispatched at approximately 6:15 a.m. Friday to the Great Falls Park area of the river, according to Bethesda Magazine.

Crews from both Montgomery County and Fairfax County searched for about six hours Friday before suspending operations for the night, MCFRS spokesperson David Pazos confirmed. The body was ultimately found between the Sandy Landing Boat Ramp and the Maryland shore.

MCFRS Assistant Chief Daniel Ogren told Bethesda Magazine that section of the river runs approximately 65 to 70 feet deep in parts, with "next to no visibility."

The search and recovery took place during extreme heat, with temperatures reaching 96 degrees over the holiday weekend.

The teen's identity has not been publicly released. His body was taken to the state Office of the Chief Medical Examiner in Baltimore for autopsy. Ogren said crews believe the teen likely drowned, but other factors still need to be ruled out. The Montgomery County Police Department is the lead agency for any death on the river.

The drowning is the second fatal incident involving a young swimmer in the Potomac in three weeks. In June, 20-year-old Nazir Bell of Germantown went missing near Billy Goat Trail A and Sandy Landing in the C&O Canal National Historical Park. Bell's body was found days later.

MCFRS Battalion Chief Tony Scott warned residents to stay out of the river entirely.

"We have lost a life every single year from that river," Scott said. "We have absolutely great county pools, local pools, recreational areas — swim over there. Hang out there. Do not go swimming in the Potomac River."