The top floor of the three-storey building housed a private school.
Officials of the Lagos State Emergency Management Agency (LASEMA) and other rescue official are now at the scene.
The rescue operations are however, suffering hitches, as rescuers are finding it hard to gain access into the building with their equipments.
One witness, Abdulazeez Elegushi, said "a quit notice was given to the owner of the building by the government after it failed integrity test", he told Daily Sun, speculating about the possible cause of the collapse.
Many people including school children are believed to be trapped inside a building that collapsed on Wednesday.
The Lagos emergency management agency said 10 people had been recovered alive since emergency responders arrived, and others beforehand.
A woman cries as the body of a child is recovered.
"All we are interested in now is to save more lives and also see how those that have been rescued are put in proper place and proper care".
Elsewhere, hundreds of local residents tried to help, passing water and helmets through to dust-covered rescuers working tirelessly to sift through the rubble, some of whom appeared to be distressed. All we are trying to do is to scale up this rescue operation.
Ambode said the school was operating illegally in the premises and that a full scale investigation would be carried out immediately rescue operations are concluded.
Onlookers crowded around in the densely populated neighbourhood in Lagos, Nigeria's commercial capital and a city of some 20 million people.
Despite efforts to renovate the area, a large number of abandoned buildings have been taken over by families or businesses, despite being dilapidated and unsafe.
The statement read: "The collapse of Lagos three-storey building is the height of criminal dereliction of duty which should attract immediate prosecution for the murder of all the officials of the Lagos state Urban Planning Department".
He added that the rescue team would remain on the scene until they can confirm that no one is left under the debris.
Over 100 people died in 2016 after a church roof collapsed in the south of Nigeria.
Trump Plan Postpones Balanced Budget Despite Deep Spending Cuts
Separately, Mr Kudlow expressed optimism that United States economic growth will surpass three per cent "in 2019 and beyond". The initial rollout lacks details on individual programs, which are anticipated to be delivered later this month.