What happens if there's a hole in an airplane at an altitude of 10 kilometers?

Which part ? i could answer tell me

Seeing as you're so high up, a hole in the plane can lead to violent decompression and a loss of atmosphere, so the flight crew needs to get more atmosphere into the plane and equalize the pressure. The way to do that would be to drop to the much safer altitude of 10,000 feet, where the atmosphere isn't as thin.