When I turned the key all the electricity shutdown, why won't it start? on 2000 Oldsmobile Silhouette

Everything was fine with it yesterday, it's really cold here right now and it seems not to like that too much, but it hasn't given me any problems. Just changed the battery out 1 month ago, filled the tank 2 days ago, so I don't think that is the issue, what else could it be?