6.

It is currently unclear whether the Titan imploded when the submersible first lost contact with its mother ship. However, Mauger did say that there has been no sign of an implosion since sonar buoys were placed in the water during search efforts.

Officials say they are still working to develop the details of the timeline, and they will update the public when they know more.

Source: https://www.buzzfeed.com/alexalisitza/7-facts-titan-submersible