In the deserted city of San Diego, California, an area of the zoo sits behind iron gates; away from the general public. The concrete facade is known as the Frozen Zoo, it's use dedicated to preserving the egg and sperm samples of the parks hundreds of species, as well as more than three thousand from institutions around the world. The samples in these refrigerated vaults vary from rare or now extinct animals to thriving creatures that reside everywhere. Started in 1986 with a similar concept to the Svalbard Global Seed Vault, the process involved constant maintenance and use of chronic freezing to keep the samples safe indefinitely. But without that maintenance and without power, can these remnants of animal species stand the test of time?
3 Months After People: After three months without power or refills of liquid nitrogen, the hundreds of egg and sperm cells have decayed and died. The hope for reviving extinct species has died with them.