Four construction workers were killed Wednesday in another deadly building collapse in Nigeria’s economic capital, Lagos.

Officials of the Lagos state fire service said search teams rescued five workers and that those workers are in stable condition.

Officials say an unknown number of people remains trapped under the debris. The building, a one-story structure in the Magbon area on the outskirts of Lagos, caved in Wednesday afternoon.

Earlier this month, a 21-story building collapsed in the Ikoyi area of Lagos state, killing at least 42 people and raising concerns among both citizens and authorities.

Experts attribute the frequent collapses seen in Nigeria to substandard building materials and poor monitoring by authorities.

“What is government doing to have prevented this occurrence? We can’t continue to be wasting lives. Every professional body has a regulatory body, we have the Nigerian Institute of Architects, we have Council of Registered Builders of Nigeria. To what extent are those regulatory bodies delivering on their mandate?” asked Festus Adebayo, founder of the Housing Development Advocacy Network.

After the Ikoyi building collapse, Lagos state authorities set up an independent team to investigate the incident. They also declared three days of mourning in the state for victims, who included the owner of the real estate company that was developing the site.

Source: Voice of America