The odds of survival for those trapped after Nepal flood

NEW YORK — For those stranded by a flood, survival depends on many factors including access to oxygen, food and water.The odds of survival for those trapped after Nepal floodCatastrophic flooding along the Nepal-China border has killed hundreds and left thousands more missing. On Monday, rescuers in Nepal raced to free hundreds of workers thought to be trapped in hydropower site tunnels that were buried in mud.Experts say the first 72 hours are critical as the chances of survival drop without access to clean water.One important aspect is whether the tunnels had emergency protocols in case of an outage or natural disaster, said disaster epidemiologist Jennifer Horney with the University of Delaware.If so, workers could have been trained on the location of exits. But the force of the floodin