On closer analysis, however, the probability of a fortified bunker actually protecting its occupants from the reality of, well, reality, is very slim. For one, the closed ecosystems of underground facilities are preposterously brittle. For example, an indoor, sealed hydroponic garden is vulnerable to contamination. Vertical farms with moisture sensors and computer-controlled irrigation systems look great in business plans and on the rooftops of Bay Area startups; when a palette of topsoil or a row of crops goes wrong, it can simply be pulled and replaced. The hermetically sealed apocalypse “grow room” doesn’t allow for such do-overs.