Dozens of people are reported to have been killed and thousands left homeless in northern Nigeria, after they missed warnings that hydroelectric dam floodgates would be opened to release rising floodwaters, according to a local news source. The death toll is said to be 39, with more than 210 settlements submerged or washed away in the days since the gates were opened to ease pressure that built up from the heaviest rains in three decades.

According to a local official in northern Niger State, where three of Nigeria’s biggest hydroelectric dams are located, it is possible that the number of deaths will increase, as the waters are still rising after more rain. The official also claimed that most people did not hear the warning and are now struggling to cope.

The local radio station is said to have failed, meaning that the message to evacuate the region had reached only a small number of communities. Some people who did hear the warning from the National Electric Power Authority, decided to stay to protect crops almost ready for harvest. Others, apparently, had no safe place where they could go.

The release of floodwaters from the Kainji, Jebba and Shiroro dams, owned by the National Electric Power Authority, is said to have swept through villages, uprooting trees, carrying away livestock and personal belongings, and dissolving the walls of mud dwellings.