The scientific director for the company that owned the Titan submersible that imploded last year while on its way to the Titanic wreckage testified that the sub had malfunctioned just prior to the fatal dive.

OceanGate's former engineering director said he had refused to pilot the ill-fated submersible which imploded more than a year ago.

OceanGate Expeditions is the company that constructed and operated the Titan submersible. The company, based in Everett, drew on expertise from the University of Washington and Washington State University to help construct its marquee underwater vehicle designed to take paying customers to view the wreckage of the Titanic.