MR-4, Liberty Bell 7 post-flight debriefing of Virgil I. Grissom. NASA Manned Spacecraft Center, Langley Field, VA, 1961. 4o. Unbound. Internal use copy issued to John van Bockel of the astronaut training office. Includes a transcript of a debrief immediately after the flight on the recovery carrier and the transcript of Grissom's full debrief at Grand Bahama Island on 21 July 1961. Also an extensive debrief transcript at Cape Canaveral on 23 July 1961. Comments from Grissom include his pilot performance, flight procedures, and detailed discussion on problems of the training program relative to recovery operations. There is extensive discussion of the unexpected hatch release which caused the capsule to sink.ALL AT ONCE, THE HATCH WENT .... but I don't think I hit that button. The capsule was rocking around a little... I don't see how I could have hit it, but possibly I did." This changed to a very emphatic confidence that he did not touch the hatch release button at all during the later debriefings. A very pointed comment by Grissom was: "If I hadn't had the neck dam (part of the space suit) up, I think I would have drowned before anyone could have gotten to me."