Last August, the San Francisco Giants and San Diego Padres were forced to sit through a delay because the lights went out at Oracle Park. The Arizona Diamondbacks cannot open or close the roof at Chase Field while fans are in the seats due to the risk of cables snapping. The Oakland Athletics have essentially tanked their organization in an effort to leave a ballpark filled with mold and animal waste that regularly has sewage leaks.
Much like any other building, ballparks occasionally run into structural problems. Most of the time, they’re a nuisance but relatively harmless; anything fairly significant is typically noticed and fixed before something bad happens (with the exception of Oakland’s sewage problem, but that’s a story for another coast).