Mermaid File: 2004 mass whale beaching?

From a message board discussion of Animal Planet's Mermaids:
"The mass whale beaching that supposedly happened in April of 2004 in Washington state doesn't seem to have occurred, though there was one later that year.

Sadly, the Navy does underwater explosion and sonar stuff that does indeed mess up cetacean sonar navigation, possibly leading to these beachings.* It's really too bad that the one true part of this thing is also the saddest."