More than 200 people died in a mine collapse in eastern Democratic Republic of Congo (DR Congo). The disaster happened in the town of Rubaya on Wednesday. Rebel authorities said heavy rains caused the mine to give way. Lumumba Kambere Muyisa, spokesman for North Kivu’s rebel governor, spoke to reporters about the tragedy. Women and children were working at the mine, digging for coltan. This mineral is important for making electronic devices like smartphones and computers. A former mine supervisor told the BBC that the site was not well maintained. This poor upkeep increased the chance of accidents and made rescue work harder. The soil in the area is fragile, adding to the risk. Many of those killed were artisanal miners, who work without formal employment. Around 20 survivors are now in hospital. A man whose cousin died called it "a big loss" for families and the community. He described his cousin as "courageous" and "ambitious," focused on supporting his wife and children. "I didn't believe he could pass away in such circumstances," the source said. The cousin's body was found hours after the accident. Governor Erasto Bahati Musanga, appointed by the M23 rebels who control much of North Kivu, visited survivors on Friday. M23 rebels, believed to be backed by Rwanda, took control of Rubaya and its mines in 2024. Rubaya's mines hold about 15% of the world’s coltan and half of DR Congo’s deposits. Coltan contains tantalum, crucial for electronics worldwide. The BBC visited the site in July 2025 and saw miners working by hand in dangerous conditions, with many open pits. The UN has accused M23 rebels of taxing mining profits for their own gain. The Congolese government in Kinshasa has been contacted for comment.