heroic efforts, 38-year-old stephen schaeffer died a short time later at the hospital. joining me from boston, wildlife biologist jeff coin and author of the book 100 heartbeats and friend to msnbc. good morning to you, jeff. good morning. when this kind of thing happens, people start freaking out and we all get worried and think you can t go into the water again. talk about these concerns, how common are these attacks and should we be afraid to go in the water? well, alex, shark attacks are truly incredibly rare. since we ve been keeping records for many, many decade, we ve only had about 2,000 shark attacks worldwide, out of which maybe about 47 confirmed deaths. so it s incredibly rare. you have about a 30% chance of dying or being struck by lightning than attacked by a shark. usually it s very rare to get an unprovoked attack. more often than not when a shark does attack, it s the result of mistaken identity.