One exception that proves the rule that an airport reverts to uncontrolled status--USAF airports must have the tower manned and operational for the field to be open, if not, the field is closed, operations are not authorized and the Class D is closed. This does not happen at a civilian airport.
Again, I have no objection to diverting, but please don't say the crew was on violation by landing--they weren't and the FAA and NTSB won't conclude they were.
LSM. The difference is he would be landing without a clearance because he would be on the wrong frequency at an operating tower. Our heroes were on the right frequency without a clearance because the tower was not operating.
GF