BRUMADINHO, Brazil (AP) — Rescue officials say the death toll following the collapse of a dam holding back mining waste in southeastern Brazil has risen to 121. Another 226 people are missing.

Lt. Pedro Aihara of the Minas Gerais state Fire Department said Saturday that some bodies may never be found under the tons of mud that swept through a rural area of Brumadinho.

Aihara says that the recovery mission will take more than a month. The decision on when to call it off will depend on environmental conditions and the state of the bodies recovered.

No one has been found alive since the day after the Jan. 25 collapse.