Nine people were killed and 53 vehicles got burnt when an oil tanker caught fire in Nigeria’s largest city Lagos on Thursday, Reuters reported. Four injured were in hospital, emergency authorities said.

The incident took place around 5.30 pm (10 pm Indian time) on a motorway connecting Lagos to the city of Ibadan, the Lagos State Emergency Management Agency said. The accident was the result of a brake failure, said the Federal Road Safety Commission spokesperson Bisi Kazeem.

The tanker, five buses, two trucks, a tricycle and 45 cars got burnt. Videos showed vehicles on fire and thick black smoke billowing across a wide stretch of road, according to Reuters.

Nigerian President Muhammadu Buhari said he was “very sad to learn of the tragic loss of lives”, and said it “seems to be one of the greatest tragedies we have seen in recent times”, AFP reported.

Fuel explosions are common in Nigeria, where oil is transported on poor roads by trucks in a poor state of repair, according to AFP.