This happened in Hanan, China. Apparently, the gas line had been cut in the first floor apartment, but the owner of the house denied cutting it. There were 7 people injured in the blast. The owner was treated for burns and 6 others (including the 60 year old man) outside were treated for injuries. No-one was living on the 2nd floor.
You heard that right, those two guys outside survived!
Video taken March 24th, 2013 (03/24/2013).