Following three days of torrential rainfall, mass wasting of mud and debris damaged or destroyed hundreds of buildings in the city, killing 1,141 people and leaving more than 3,000 homeless.

According to Jamie Hitchen of the Africa Research Institute "the government is failing to provide housing for the poorest in society", and when attention is paid to issues such as unregulated construction, it is received only after a crisis.

[7] The construction of large homes in hillside areas and unrestricted deforestation for residential purposes weakened the stability of nearby slopes and caused soil erosion.

[7] Within a decade leading up to the disaster, Sierra Leone cleared approximately 800,000 hectares (2,000,000 acres) of forest cover – the country's civil war, fought between 1991 and 2002, was also a cause of deforestation.

[11][12] Overlooking Freetown, Sugar Loaf mountain partially collapsed, triggering mudslides in the early morning of August 14, which damaged or completely submerged several houses and structures, killing residents – many still asleep – who were trapped inside.

[1]: 14  Highly mobile, the saturated debris flow from the collapse of the upper mountainside, carrying mud, large boulders, tree trunks, and other material, advanced toward the main river channel, Lumley Creek, with a wall of flood water leading in front.

[1]: 17 Local organizations, military personnel, and the Red Cross of Sierra Leone contributed to immediate excavation and recovery efforts, working amid rainfall.

[17] Additional evacuations took place when aerial images of a hillside adjacent to Sugar Loaf revealed the threat of another mudslide which could impact a much wider area.

[21] Response teams were deployed to two voluntary relocation centers, the Old Skool compound in Hill Station and Juba barracks in Lumley, where workers distributed sanitation and medical supplies.

[23] Unsanitary waters raised fears of cholera; however, workers provided storage tanks, purification tablets, and instructional courses on hygiene to help prevent an outbreak of waterborne diseases.

[27] President Ernest Bai Koroma addressed Sierra Leone in a national broadcast August 15, declaring a state of emergency and announcing the establishment of a relief center in Regent.

Already in the country, numerous international organisations acted immediately, providing basic supplies and services – from food and shelter to personal counselling and mobile phones.

[40] Three months removed from the disaster, the Sierra Leone government announced the closure of emergency camps, which housed many families awaiting financial assistance.