The nation is headed toward a “very tragic” fall unless Washington moves decisively to bring the budget under control, Mayor Bloomberg warned yesterday.

Saying lawmakers missed an opportunity to “put our house in order,” Bloomberg issued a gloomy prediction.

“We are headed down a road that has a very tragic and bad ending for America, and unless we find ways to stop this increase in the deficit . . . which is going to have to be done through enhanced revenues and real cuts, we are headed towards a great fall,” he said.