Vlad, pressurised a/c aren't like a balloon that's completely sealed to contain the higher pressure air. They're more of a seive, continually leaking but with air being pumped in faster than it can leak out. An outflow valve is used to finely moderate the rate of leakage at one or two points to control the internal pressure.
All it takes for a depressurisation event is for the overall leakage to exceed the pressurised air inflow ie an exacerbation of what is happening normally & continuously. That doesn't necessarily imply catastrophic breakup.