The Maine Warden Service says the 9-year-old girl who drowned Friday in the Mattawamkeag River was trying to swim across the river with her mother’s friend.

Lt. Adam Gormely said Sunday that section of the river, known locally as the Heaters, is not safe to swim in. The rapids are swift and the currents strong.

Gormely said the girl tried to swim across the river with Michael Tait of Lee. The girl’s mother, Charis Rolling of Lee, was on the riverbank with two other adult friends and two children. Gormely said he would not release the name of the drowning victim.

Gormely said the river currents separated Tait from the girl. When he tried to help her onto rocks, she slipped away. Her body was found Saturday morning about a quarter-mile downstream from where she went in. She was not wearing a life jacket, Gormely said.

The girl had been camping with her family at the town-owned Mattawamkeag Wilderness Campground and Park.

The Parent Teacher Association for Maine School Administrative District 30, which included the Penobscot County town of Lee, posted a message on its Facebook page Sunday.

“We’d like to extend our deepest condolences to the family in Lee that lost their precious child this weekend,” the message said. “No parent should ever have to go through what you are going through and no words are enough to express our sorrow.”