Nigerian emergency officials said at least eight people have died and nearly 40 others have been rescued from a collapsed building in Lagos.
An unknown number of children are among the dead or are trapped in the rubble of the three-story building that housed a primary school.
Onlookers said a school with about 100 students was located on the building's top floor.
Ambulances, fire trucks, and heavy building equipment were standing by to help with the search-and-rescue effort, which continued as night fell.
A Reuters reporter saw a boy of 10 being pulled from the rubble, covered in dust but with no visible injuries, and the crowd erupted into cheers as another child was pulled out.
The building was located on the Ita-faji on Lagos Island, the oldest part of the city.
Lagos state Gov. Akinwunmi Ambode said the buildings in the neighborhood should have undergone integrity tests, but that the building's owners had not complied.
Newly re-elected President Muhammadu Buhari tweeted he "was saddened by the news" and charged the Lagos government to make sure "such tragic developments do not recur."
I charge the Lagos State Government to do all that is needful, so that such tragic developments do not recur.— Muhammadu Buhari (@MBuhari) March 13, 2019
Building collapses are not uncommon in Nigeria. In 2016 more than 100 people died when a church collapsed in southeastern Nigeria. A five-story building in Lagos collapsed that year as well, killing at least 30 people.