It's possible that the OP had been accessing the old http site as RtS described, maybe using an old bookmark. If so he probably would not have been able to log in because the link would have taken him to the new https site which was unavailable.

If he had already been signed in he would probably have been able to post - as RtS himself did at 05:38 and 05:43 AM that day - when I think the main site was unavailable.