Video shows a whole street being flung into the air by a suspected gas explosion in South Africa

• A massive blast rocked Johannesburg's financial district on Wednesday, killing one and injuring around 50.
• The suspected gas pipe explosion, which threw vehicles into the air, was caught on security footage.

A huge blast rocked the financial district of Johannesburg, South Africa, late on Wednesday, leaving one person dead.

The explosion killed one person and injured around 50 others on Lilian Ngoyi Street, according to South African newspaper the Mail & Guardian.

Security footage of the blast shows multiple vehicles being flung into the air at once, many landing on their sides. Several street vendors are seen coming inches from being crushed under vehicles. The man killed was found under a vehicle, the Associated Press reported.

Reuters shared the footage in a tweet:

Three possible causes have been outlined by authorities, all of them connected to the gas pipe, the Globe and Mail reported.

Methane gas, arising from sewage entering the stormwater system, could have ignited, city manager Floyd Brink told a press conference attended by the paper.

"The second possibility that we have considered is the ignition of natural gas mixed with air, which is oxygen in this case, in the underground stormwater drainage system of the service ducts," he reportedly said.

"The third and last possibility that we have is the ignition of gas from a gas pipe burst."

In any case, the investigation is complex, he reportedly said. Structural engineers have not found any problems with the nearby buildings, he said.

The city council announced it had closed several roads surrounding the street where the explosion took place.

Some electricity substations were taken offline while the city assessed the impact, the council said.