Are there failure modes that cause loss of pressure but not rapid, unplanned disassembly?
The 3-man crew of Soyuz 11 died when a valve was jolted open, venting out all the cabin air supply. Soyuz was redesigned after that accident to carry two crew in pressure suits instead of 3 crew in shirtsleeves. (I believe they now carry three in pressure suits.)
More generally there are any number of failure modes that could depressurize the cabin of any crewed spacecraft without destroying the vehicle. It's common, for example, for crewed capsules to have hatches which can be opened via explosive bolts; on Gus Grissom's Mercury-Redstone 4 flight, the hatch blew open unexpectedly after splashdown. If a failure like that occurred at high altitude or in orbit, the cabin would quickly vent to space without any significant airframe damage.
In such a case, it would be unlikely that the spacecraft could reenter safely, since there would be thermal, drag, and center-of-gravity issues. A micrometeoroid puncture could likewise depressurize a spacecraft, and if small enough, it could be repaired and reentry would probably still be possible, depending on the location.