Not a webmaster, but would like to know:
Does/can the google crawler system send a notification email to the registered webmaster of a website, if something like this happens? This could be deemed unsolicited, but would in a huge majority of the cases be more than welcome!
All these errors are reported in Webmaster Tools in the Diagnostics section. Verify your site and you'll have access to this and a wealth of more data.
Also, we do send notifications in Webmaster Tools, and you can confgure those to be delivered by email too. I'm not sure if we send messages for these kinds of serious crawl errors, so I'll need to check. If not, that's an interesting idea I can ask the team to think about.