"A disaster waiting to happen" is a commonly used phrase to describe an event or situation that is likely to result in a calamity. Synonyms for this phrase include a time bomb, a ticking time bomb, a powder keg, a potential catastrophe, a ticking bomb, a catastrophic event, impending doom, looming disaster, and fatal flaw. Each of these synonyms can be used in situations where there is a potential danger that could have serious consequences if left unaddressed. It's important to recognize these dangers and take proactive measures to prevent any potential disasters that could occur if they are not addressed promptly.