Day off from Office/School ...
Some interesting circumstances that have occurred in my life for which I wasn't able to go to my school or office

• Ammonia leak in a nearby meat-packing factory in South San Francisco, which resulted in the entire office district being closed
• Firing by terrorists on a school bus carrying children of Army personnel, belonging to my school in Srinagar(Kashmir) (fortunately no one was killed)
• A bustling religious fair near my office in Pune, which resulted in all approach roads being shut off, and an unbearable decibel level for work
• A curfew due to religious riots between Hindus and Muslims in Balasore(Orissa)
• Incessant rains in Bombay resulting in 4-5 feet of water outside the housing complex, resulting in a no-show at office

Feel free to add in the comments any such interesting incidents that have resulted in you having to forcibly take a day-off.
One that I can think off is the fact that schools and some offices were shut down due to swine flu threat.