Emergency worker at the explosion scene.

An elderly couple died and eight others were injured after an explosion in a residential building early Friday in Shanghai.

It happened at around 0:40 in a six-story building in the Baoshan district. The third through six floors collapsed.

Ten people were rushed to hospitals. Despite doctors' efforts, an elderly couple died from serious injuries. Among the other eight injured, two were in serious condition.

"I heard a big bang and then I fainted," said a 65-year-old man who was receiving treatment. "After I woke up, I found I had fallen from the fifth floor to the fourth."

About 60 other residents were evacuated to nearby hotels as the building was seriously damaged.

An initial investigation showed the explosion was probably caused by gas leak.