SLK Headlight bulb problem

99 SLK Compressor, I had a low beam out 2 weeks ago after the car sat for a month (high beam fine). I replaced it and this morn, I started car and the same low beam just blew again ( high beam fine). Any feedback, its it just a chance blow out or could there be wiring issues?
Terry

If the car's been sat for a while check for water leaks (if not garaged of course). If not, probably the bulb holder has burnt contacts. That doesn't normally blow them though, just cause them not to work.