Mom of Titan Sub Victim Says She Gave Son Her Spot

More details about the Titan submersible catastrophe are coming to light.

Eight months after the OceanGate submersible imploded, a new documentary is highlighting the harrowing search and knocking sounds rescuers heard at the time, which ultimately fostered hope of finding its five passengers alive.

"The symmetry between those knockings is very unusual," former Navy submarine Captain Ryan Ramsey said during ITN's The Titan Sub Disaster: Minute by Minute trailer. "It's rhythmic, it's like somebody is making that sound, and the fact that it is repeated is really unusual."

The documentary, which is set to air March 6 and 7 on Britain's Channel 5, chron…