In article ,
says...
Hi folks,

My brother and I were recently lifting some chipboard flooring in my
house in order to lay a new electrical cable. Because the chipboard was
tongue & groove, rather than ripping out the whole floor, we decided to use
a circular saw to just cut out the section we needed to get at. So little
bro is happily sawing away when water starts to gush out!

Maybe next time you'll set the saw blade to the thickness of the floor
:-)