According to Mr Umahi, the standard engineering design for headroom is 5.6.
The minister said there would be remedial work on the bridge.
The closure will affect the stretch between Apongbon and Ijora Olopa.
The move followed a recent joint inspection, which revealed significant damage to eight piles.
Mr Bakare-Oki said engineers had been working for four to five hours, causing traffic congestion.
Mr Giwa said LASTMA had been mobilised to intensify surveillance and operational presence along the affected corridors.
Mr Umahi said that President Bola Tinubu’s administration was committed to improving the country’s infrastructure.
Ms Kesha said the closure would affect traffic from Ahmadu Bello Way and Adeola Odeku towards Marina, Eko Bridge, and Onikan by Zone 2.
The federal government has expressed concern about speeding on the rehabilitated Third Mainland Bridge in Lagos.
Mr Cole added that the fellow petitioned the state Commissioner for Environment, who ordered the demolition of the illegal structures.
