About 65 million years ago, a giant space rock slammed into Earth. The asteroid’s impact sparked a wave of destruction that wiped out the dinosaurs. Now researchers have a clearer picture of that fatal day.

Scientists from the University of Texas drilled 1,335 meters (4,380 feet) into the crater left by the asteroid on the coast of what’s now Mexico. They discovered rock deposited in the 24 hours after the collision. The sample contained sediment carried by a tsunami—or giant ocean wave—triggered by the impact. Heat from the blast sparked wildfires that left traces of charcoal. There was also evidence that the impact vaporized rocks on the ground, sending huge amounts of dust into the air.

“Dust in the sky reduced sunlight, causing much of the world’s temperatures to drop below freezing,” says Sean Gulick, one of the project’s chief scientists. That killed plants around the globe, dooming dinosaurs to starve.