An Aztec sacrifice of 20,000 people over a period of four days in 1411 is examined. The sacrifice consisted of a sacrificial priest cutting the person's skin beneath the rib cage, reaching up and cutting the arteries and veins attached to their heart and pulling it out. Then the body was pushed down the stairs of the altar. After an examination, it is proven that this many people could be sacrificed in such a small amount of time.