Strongly urge everyone here and those you know and love to buy a “Storm Safety Whistle” which is 100% louder than standard police whistles and can be heard under water. The Storm Whistle is currently used by the U.S. military and preferred 3-1 by police officers. Can be found in sporting stores for $12 or go to stormwhistles at stormwhistles dot com to purchse. (we are not allowed to post web sites I don’t think). I have one and it’s a must have for your own safety. It’s a matter of life or death.
The problem with this whistle is the same as the problem with any other device. One must be able to get to it. I doubt a whistle, gun, mace, or anything would’ve helped this girl. But until details come out, it is only a thought.