MANCHESTER, N.H. (AP) – An 11-year-old boy drowned after jumping about 40 feet from the Queen City Bridge into the Merrimack River.

Authorities said Bol Mardol of Manchester jumped off a trestle just after 7 p.m. Sunday night. Manchester District Fire Chief Daniel Goonan said the boy did not know how to swim and panicked after plunging into the water.

Witnesses who heard Mardol’s two young friends screaming jumped into the river to try to rescue him.

“We couldn’t find him. The water was pitch black,” said one witness, Ryan Morgan, 17.

Morgan said the boy was one of two children who jumped off the concrete piling under the bridge. The boy was encouraged to leap, he said.

“I saw the second kid jump. He was bobbing in the water and then went under,” said Morgan.

A security guard overseeing a nearby construction project called 911 after seeing the boy jump.

A search team using an underwater camera found the boy’s body about two hours later in about 15 feet of water.

Police warn that the area is not safe for swimming.