Sounds like it went bad, do a seach for "replace ignition cylinder" and you will find lots to explain how to do the work. Be sure that the incline did not jamb the lock tight. If you are not positive that the wheel is not just forced against the lock, jack up the front wheels off the ground,this will take off all the stress that the incline might be causing the lock to jamb. if the wheels are off the ground and the lock is still jambed, you have a bad ignition cylinder and Lord help you as you learn to fix it, it is not fun and not cheap, but it can be a DIY job

__________________
Christopher Henkel
1990 190E 2.6 - Arctic white SOLD
1986 190E-16v - Blauswartze
1993 300CE - SOLD
2003 W208 CLK 320 Cabriolet - Magma Red