Break the keel off a sailboat and leave a 10 inch wide by 5 foot long hole in the bottom of the boat.
The boat sinks in 15 seconds, the other 14 minutes and 45 seconds you float in the water (assuming you weren't down below when it happened) and wonder what happened.
How do I know this? I'm not answering that but . . . .
That used to have a keel attached to it.