At least 30 people were killed in a massive landslide in Guinea on Sunday when a mountainous open-air landfill collapsed and buried nearby shacks, trapping numerous victims beneath a mass of garbage.

The incident happened at Dar Es Salam, the largest waste dump in the West African country’s capital, Conakry, according to a report from The Associated Press.

Guinea News reported that the weight of the waste caused a three-story building beneath it to cave in.

Authorities said heavy rainfall also washed over the refuse overnight, creating hazardous conditions at the landfill, according to the AP

Six people were seriously injured and several homes were destroyed in the incident, according to reports. Officials launched a search-and-rescue operation to find any survivors.

The AP reported that the landfill was originally scheduled to close Sunday after officials warned of hazardous conditions, citing Lt. Col. Baldé Mamadou Bailo, the sanitation officer for the military engineering battalion.

The decision followed reports of a similar incident at the landfill in recent years, raising concerns about its safety

As a precautionary measure, residents who lived near the site had also been given eviction notices and were forced to vacate the area, the AP said.

However, many people remained nearby at the time of the disaster, according to reports.

“We will ensure that the remaining families are relocated elsewhere,” Dienabou Touré, the minister of territorial administration and decentralization, said at the scene, according to the AP.

Reuters reported that the landfill suffered a similar incident in 2017, when torrential rains caused a mudslide that killed at least eight people.