At http://heiwaco.tripod.com/news8.htm you can read a big article about the causes of the Costa Concordia tragedy. Heiwaco states that the watertight doors below the bulkhead deck were not closed at the time the ship struck a reef.
Heiwaco also has an alternative view about the capsizing of the MS Estonia back in 1994.
It is quite possible that some of the watertight doors were open. Doors have 3 designations, A, B and C.
Class C watertight doors must be closed at sea and can only be opened to pass through.
Class B doors can be open at sea if someone is working in an adjacent compartment
Class A doors can be open at sea unless the ship is navigating in confined waters or in restricted visibility.
If the sail past of Giglio Island was being treated as a normal sea passage rather than a "stand-by" situation then it is quite possible that the A and B class doors in the machinery spaces were open at the time.
It is also possible that someone had nipped into one of the spaces accessed by a class C door for a couple of minutes and had left the door open until they left when the collision occurred.
We won't know the truth until the results of the formal investigation is published, and even then it is possible the
true truth won't come out.
