“How pray tell?”
It’s happened before. If just one of the upper levels fall the weight will exceed the carrying capacity of the floor below it shearing the supports. A chain reaction ensues and the floors drop.
An explosion isn’t necessary, just poor engineering, substandard materials, careless installers, or a myriad of other factors.
L
“Gently, Willis and his family led the woman with them to the first floor. The garage was flooded. They lifted the woman over a wall that had collapsed near the pool, and over a stretch of broken tiles. “At the moment, [focusing on saving the woman] takes your mind off it,” Willis said. “There is something else going on. When they got to the bottom floor, they found it had sunk at least three-four feet. There were chunks of concrete. There was debris”..
Give me a fer instance of when it happened before.