Thats the MAIN reason why we took our pond out, we were worried that the little one would fall in without us being around and drown, our lab is an excellent swimmer, but these little ones wont be able to get out.
to answer a question to the above post ( all dogs can swim ) but these babies are so tiny that they wont be able to keep paddling till someone rescues them.
Like the warning about bra's also be aware not to leave anything laying around on the top of the crate, i know of a lab pup on a lab forum that was in his crate and the child left a schoolbag on the top, during the night the lab pup started playing with the leach of the bag and got strangled
we can never be too carefull!