I have confession to make

I have confession to make that I had suffocated two lovely goldfish yesterday afternoon after clean up their tank and filled with new water.
I am so sorry for them :_( Just can't believe that they were all gone ;_; I were tried to pump as many Oxygen into water as possible, but failed. :'(
Wish it was not Memorial Day, then they can live longer. Wish to see they begging food while I waving my hand to them.
This is a big mistake that I had made. BIG BIG BIG mistake!!!