Facebook has activated its safety check feature following the collapse of a building on 63, Massey Street, Ita Faaji area of Lagos Island.

Safety check allows people in the affected area to let friends know they are safe. It also allows people to offer and render help to one another during a crisis.

Lagos residents have since started using the feature on Facebook, observation by our correspondent on Thursday showed.

When an incident such as an earthquake, hurricane, mass shooting or building collapse occurs where people might be in danger, a global crisis reporting agency alerts Facebook.

At least 10 persons, including four schoolchildren, were feared dead on Wednesday when a three-storey building, which housed a school, Ohen Nursery and Primary School, and residential apartments, crumbled around 10 am.

Rescue efforts have been underway since the incident occurred, with about 50 persons rescued by officers of the Lagos State Emergency Management Agency and other emergency responders, including the National Emergency Management Agency, the Nigeria Police Force and the Nigeria Red Cross Society.