I was routing this cove in a piece of Ash. I had featherboards in place and I was using a push block. The router bit caught a wayward grain exclusion which twisted the board slightly between the fence and horizontal featherboard. One face of the cove was then wedged between the router bit and the pressure from the featherboard.
Then BOOM. The workpiece flew across the shop and hit the wall with a loud bang. Click the image above. You can see each point where the router bit grabbed the work as it was flung in to the wall.
My brother curiously suggested that it was going at about 10-15m/s and packing about 40 joules. That would be painful enough if it hit you, but the real danger is if your fingers were pulled in to the router bit.
Stay safe! Even when doing everything right, accidents still happen. It’s up to you to make sure those accidents don’t cost you a finger.