Shop forgot to put oil!!!!

[guykoh]

Hi guys I just purchased a 1998 E300TD and took it to my mechanic who specializes in mercedes to do an oil change. This was done a few days ago. I drove home, which is about 10 miles from the shop. This morning when i went to start the car I heard the car knocking. I turned off the engine and checked the oil only to find that it was at the minimum mark! Do you think I may have done any damage to the engine? Any help is appreciated. My car has 95K miles on it currently.