In traditional SimCity fashion, an [un]expected disaster can easily wreak havoc upon your city. Everything thing from meteorites and tornadoes to rampaging monsters are at your disposal once you unlock them. Disasters become available once you complete the associated achievement. The requisites for these aren't really explained so we've come up with this guide to help you unlock every disaster.
Description: Have 200 tourists arrive on flights at the Municipal Airport in a day to gain access to the Meteor Strike disaster.
This one isn't too difficult to unlock. First, you'll have to spend the $85,000 to place the Municipal Airport. The next step is to secure a large number of tourists. To do this, add a Department of Tourism to the City Hall, and then use the City Specialization menu to place tourist destinations. As you place more destinations, tourism will increase until it hits the required number.
Description: Mine 100 tons of coal or raw ore in your city to gain access to the Earthquake disaster.
This one involves a bit of waiting around. Under the City Specialization menu, spend the cash to construct a coal or ore mine. Once placed, it will mine at twenty-four tons per day. You can add additional shafts to increase this rate, but in either case, this achievement will pop once you've extracted 100 tons.
Description: Ship any resource to a Space Center Great Work to gain access to the UFO Encounter disaster.
This one will take some time to unlock. First, you'll need to open add a Department of Education - a $15,000 purchase - once you upgrade to a City Hall. Next, you'll have to open schools and community colleges until you reach 1,200 students enrolled per day, unlocking the University. Once you've built the University, you'll have to enroll enough students to unlock the School of Engineering. With that unlocked, perform the costly Space Station research project. With the Space Station built, you'll be all set to start using the UFO Encounter disaster.
Description: Burn 100 tons of garbage in an Incinerator at the Garbage Dump to gain access to the Big Lizard disaster.
This one is really a matter of waiting. Once you've built a garbage dump, install an incinerator - this will slowly burn away trash. Once you've burned 100 tons, the achievement will pop. Install multiple incinerators to speed up the effect.
Description: Have 24 Wind Turbines at Wind Power Plants in your city to gain access to the Tornado disaster.
This is one of the easier disasters to unlock. Start by using a Wind Power Plant to power your city. Once placed, create a long service road - it'll need to hold 24 turbines, after all. Once you've got the road, simply start plopping down turbines. You'll need 23 in addition to the one you start with, so be aware of the cost. Twenty-three turbines at $5,000 each will run you a total of $115,000.
Description: Add a Diagnostic Lab to a Hospital and have 15 Sims die in a day to gain access to the Zombie Attack disaster.
Start this one by following the same steps as the UFO Encounter disaster unlock. Once you've built the university, spend $40,000 to construct a School of Medicine. Once complete, perform the costly, but necessary research project to unlock the Diagnostic Lab. Attach it to a hospital, and prepare for things to get a little dark. To guarantee the fifteen Sim deaths, temporarily turn off all health, police, and fire facilities. This will allow sickness, crime, and fire to run wild, causing the required number of deaths and unlocking the disaster. Just be sure to turn them back on after!