Scientist urges a halt to all Titanic trips

STORY: The former ABC News science editor who got trapped in a Titanic's propeller and survived the expedition in 2000, held back the tears while describing the feeling of being down there at what he called a "sacred place."

Guillen called for a thorough international investigation into what happened to the touristic submersible that went missing on Sunday (June 18) and triggered the relentless search for the five passengers on board.

An unmanned deep-sea robot deployed from a Canadian ship discovered the wreckage of the submersible on Thursday morning about 1,600 feet (488 meters) from the bow of the century-old wreck, 2-1/2 miles (4 km) below the surface.