Day of Honor - S4-E3
Corrected entry: How could Tom and B'Elanna transport themselves from the shuttle into space using voice command if the comm system was down?
Correction: The comm system in Star Trek is generally regarded as the means to talk to other ships/crewmembers not in the room. Talking to the computer is regarded as a separate system. I find it more strange that for once the transporter wasn't the first thing to break.
Correction: Because Federation ships are designed to make sure that the passengers survive - they have several safety mechanisms so whilst other systems could go off line the emergency transporter should be one of the last things to go and often comes with its own power & certain systems.