The water pressure challenges facing missing Titanic sub

Butch Hendrick is president and founder of Lifeguard Systems, which conducts dive training for public safety officers, and has been instructing dive rescues for over 35 years. He joined CBS News to talk about the avalanche of challenges search and rescue teams are trying to overcome as they look for the sub that went missing on a dive to the wreck of the Titanic.
Source: CBS Minnesota