The unstable slopes of an unauthorized gold mine pit on Indonesia’s Sulawesi island gave way on February 24, 2021, burying workers. Many were rescued, several died in the collapse. News reports noted that the mine was illegal. Heavy rains caused a landslide in the remote village of Buranga on Sulawesi island’s Parigi Moutong district. Some of the victims were women while some 16 survivors were pulled from the debris. Officials said intense rainfall and unstable soil structure at the illegal mining site may have contributed to the landslide.
Illegal mines typically will not have the proper safety and structural support necessary for such an opening. Even under normal conditions, slopes or trenches can collapse. These types of illegal operations are common in Indonesia and the number is rising as people seek jobs. Fatal occurrences like this are common every year.

Nine people were killed by a landslide at an illegal gold mine in Sumatra in 2020.
Sixteen died and eighteen more were injured in the collapse of an illegal mine on Sulawesi island in 2019.
Sources
ABC (Australia) news https://www.abc.net.au/news/2021-02-25/indonesia-gold-mine-collapses-sulawesi-island/13193560
Al-Jazeera https://www.aljazeera.com/news/2021/2/25/indonesia-hunts-for-missing-after-mine-collapse-kills-three
The Straits Times https://www.straitstimes.com/asia/se-asia/indonesia-hunts-for-missing-after-mine-collapse-kills-three