Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

Raphaël, it looks like your latch-out has rotated. These are secured through the crankcase with a bolt. It likely just came loose, but it also appears the steel piece on the brass carrier has also broken off in addition to the obvious damage to the flywheel.
 
This should be a lesson to us all- be sure to check torque on critical fasteners regularly. Being made of aluminum with steel bolts, I'd think no loctite was used. I did not use any when I reassembled, just torqued and plan to retorque later.