It's not known how many people lived in the apartments that made up the rest of the complex.
Ibrahim Farinloye, spokesman for the National Emergency Management Agency's south-west region, said a three-storey building came down at around 10:00am local time.
TVCNEWS.TV has gotten reports from its correspondent, Theophilus Elamah who tells us that 12 persons have been confirmed dead while 42 injured are now receiving treatment.
NAN earlier reported that a teacher, trapped with about 15 pupils under the rubble, called to seek for help, while Julius Berger and other emergency services were on ground to assist in the rescue operation as at 2.48 p.m. TVC Correspondent, Theophilus Elamah reports.
Scores of children are feared trapped after the school collapsed in Nigeria.
'For now we don't have any word on casualties as we are still busy with rescue work, ' he said.
Ambode said the school had been set up illegally and that buildings in the area were undergoing integrity testing.
In chaotic scenes, panicked parents, local residents and shocked onlookers rushed to the area as police, firemen and medics staged a massive rescue operation.More news: Serena Williams retired from her Indian Wells encounter with Garbine Muguruza
Insisting that political influence in Lagos Island has greatly contributed to the incessant collapses in the sprawling environment, Awobodu said the way forward is for the state government to as a matter of urgency set up a special task force to check the rate at which buildings are collapsing in the area.
Rescue efforts unfolded in the densely populated neighbourhood in Lagos, Nigeria's commercial capital and a city of some 20 million people.
Unless something urgent is done, we may be witnessing more building collapses, as over 1000 buildings in Lagos Island have been allegedly certified distressed.
Presidency Muhammadu Buhari said in a statement he was "extremely saddened" by the building collapse.More news: Elon Musk's SpaceX capsule splashes down off Florida coast
In Lagos that same year, a five-storey building still under construction collapsed, killing at least 30 people.
Over 100 people died in 2016 after a church roof collapsed in the south of Nigeria.
Such disasters are all too common in Nigeria, where new construction often goes up without regulatory oversight and floors are added to already unstable buildings.More news: Trump's 2020 budget request to seek $8.6 billion for border wall