parish north of new orleans. officials say the failure of a river lock is imminent. about 1,200 homes are in that area are under evacuation. in iowa president obama kicked off four days of campaign stops before heading to the democratic national convention in north, and gop nominee mitt romney was joined by his running mate paul ryan at a rally in jacksonville today. now, back to "caught on camera." welcome back to "caught on camera." i'm contessa brewer. professional rescuers try to train for every scenario. but by its nature, a rescue usually involves some element of danger. so what happens when things go horribly wrong, when things are turned upside down and it's the rescuers who need rescuing? a deadly accident. nine mountain climbers tumble one after another into a crevasse at mt. hood in oregon. a helicopter swoops down for a daring rescue into thin air,