Hi ...
Since you probably can't empty the cache from the menu bar before it crashes...
Go to ~/Library/Caches/com.apple.Safari/Cache.db (or ApplicationCache.db)
Move the Cache.db file to the Trash.
Try Safari. If it crashes again, post a crash report so we can try and help you.
Safari Crash Log: If Safari has just crashed, press the Report button on the CrashReporter dialog box to view the crash information.
Copy/paste the entire contents of the Crash Reporter window into your reply. If the crash report dialog does not appear or the crash is hard to reproduce, crash logs can be retrieved from the ~/Library/Logs/CrashReporter> folder.