IIS7 Application Pool Crash

I am running IIS 7.0 on Windows server 2008 R2 and created 1 Application Pool per site and I have 1 site which is causing the application pool to stop. These are the following errors in the Event Viewer:

This shows several times:

A process serving application pool 'Pilot.Mobile.SyncV2' terminated unexpectedly. The process id was '3620'. The process exit code was '0x80131506'.

Then I get this:

Application pool 'Pilot.Mobile.SyncV2' is being automatically disabled due to a series of failures in the process(es) serving that application pool.

Two Things- How can I findout why this is crashing e.g. tools or scritps, also has anyone get any scripts I can run on a schedule task that will check the application pools and if 1 is down it will restart it and email me.

Here's a list of "Useful tools and add-ons for IIS troubleshooting and IIS7".

Tess Ferrandez (ASP.NET Escalation Engineer at Microsoft) has a good blog on debugging.

I don't have any scripts to give you. We use Nagios/OpsView to monitor websites/servers and notify us.