A broken rail caused the rail crash (must)
A broken rail must have caused the rail crash
The houses didn't collapse in the earthquake because of a design error. (can't)
The houses can't have collapsed in the earthquake because of a design error.
The flight crew fell asleep due to cabin depressurisation and lack of oxygen. (fallen)
The flight crew must have fallen asleep due to cabin depressurisation and lack of oxygen.
The aircraft didn't have a mechanical failure (had)
The aircraft can't have had a mechanical failure
The substandard concrete didn't cause the disintegration of the bridge. (can't)
The substandard concrete can't have caused the disintegration of the bridge.
The captain wanted to save time by steering close to the headland. (have)
The captain must have wanted to save time by steering close to the headland.
The captain didn't realise that the depth of water in the channel was insufficient. (can't)
The captain can't have realised that the depth of water in the channel was insufficient.
The rail suffered thermal shock due to excessive heat. (Must)
The rail must have suffered thermal shock due to excessive heat.
The Warsaw radio mast collapsed because of human error. (have)
The Warsaw radio mast must have collapsed because of human error.
The cables securing the mast didn’t fasten correctly. (have)
The cables securing the mast can't have fastened correctly.
