66 million years ago, a massive 17km wide asteroid impacted what is now the modern day Yucatan peninsula at 25km/s. The immediate collision was so violent that the resulting crater floor was briefly deeper than the Mariana Trench while the crater rim was briefly taller than Mt. Everest. In total, it killed off 75% of all animal and plant species on this planet, including the dinosaurs.

The linked video is a real time demonstration of the catastrophic events that would occur within the first hour after impact if a similar asteroid were to hit Earth today.