You can read more about it here:
The incident is not over yet, though the market site is back at the moment is up again. The community site, hosted on a different service, is still not up.
Although it's outside of our control, we apologize for the inconvenience. We will post more information here when we learn more from Amazon and Heroku about what happened.
Heroku posted an explanation of the event here: https://status.heroku.com/incidents/1892
AWS only sent a report to their direct customers, but we are only customers via Heroku.