Bugs, consistency errors, user-requested dumps, hung schedulers, probably a few more. Open up the text dump file and have a read through.
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability
We walk in the dark places no others will enter
We stand on the bridge and no one may pass