HTTP Error 503. The service is unavailable.

Hi Guys - 

I deleted a custom package but didn't stop the service (not even sure which service in D365 corresponds to AOS service. World wide web publishing?) later when I try to run the application through VS (after building and syncing it) or access the URL, I get the following error. 

Service Unavailable

HTTP Error 503. The service is unavailable.

I checked the service Microsoft Dynamics 365 for Operations - Batch Management Service was stopped (not sure how) so I started it. Still getting the same error. 

Any suggestions? 

-Fahad