Thanx for the replys and welcome's!
No, I did not checked the battery yet. The car died at my work, so most likely I will get it towed back home where I have some tools. I will post pic soon, tho the car is a great 50-footer

vstech, I hope its just a seized starter as well...I drove the car for ~250 miles before this incident, never a hint of any engine problems, upon arriving at work no noises/rods coming out for some air etc. Good suggestion on 27 mm, I will do that first