Rescue operations have ended at the site of a Lagos, Nigeria, building collapse, an emergency services spokesman told CNN Thursday.

“We have searched all the debris and gotten to the last floor of the building, there are no more survivors,” said Ibrahim Farinloye of the National Emergency Management Agency.

At least eight people were killed when a three-story building housing a school collapsed Wednesday morning in Nigeria’s commercial capital, Farinloye told CNN.

Around 40 people have been rescued from the building, which collapsed in the Ita-Faaji area of Lagos Island, he said.

The total number of deaths remains as yet unknown but it is certain to be more than eight people as the building is situated in a densely-populated part of the mega-city, which is home to around 20 million people.

Lagos State governor Akinwunmi Ambode, who visited the scene on Wednesday, said the school was not authorized to operate in the building, which was designed solely for residential purposes.

“The building is not technically a school; it is a residential building that was actually accommodating an illegal school, so to speak, on the second floor,” he said.

Ambode added that many houses in the area had structural problems and would be demolished.

A woman cries out at the site of a collapsed building.
A woman cries out at the site of a collapsed building.

Anxious parents waiting for their children to be rescued in the building told CNN Wednesday, many buildings in the commercial hub in downtown Lagos are not safe.

“A lot the buildings here are not safe even from looking at the building, you should know no school should be here,” Wale Wasiu told CNN.

Building collapses are frequent in Nigeria.

At least 100 worshippers were killed in a church in the southern state of Akwa Ibom after the roof caved in during a Sunday service in 2016.

In 2014, more than 70 people died after a two-story guest house in a church collapsed in Lagos.