Tragic, but yet stupid at the same time.
1.) It looks like they stood still when the water was just at their ankles. They were only 10 feet away from land, so a quick 2 - 3 second dash, and they're home free.
2.) There were about 30 other people there, in the forest, so what were they doing? Throw a fallen tree into the water, or pickup a large stick off the ground and hold it out, instead of just standing there and saying, "OMG, look! I think they're going to die!"
Easier said than done in a panic situation, but nonetheless.