BERLIN (AP) — Two young brothers who drowned in a lake in western Germany were British tourists, authorities said Friday.

The boys, aged 7 and 9, were reported missing by their parents at a designated swimming area on Eiserbach Lake south of Aachen, near the border with Belgium.

Rescuers were able to retrieve the children from the water and they were taken to hospitals in Aachen and Cologne but they later died.

Aachen prosecutors said they were investigating whether the deaths were the result of negligence.