President Barack Obama has said that the US economy is passing through the worst crisis of history after 1930 and any failure in overcoming it could turn the crisis into a catastrophe. Talking with journalists in Washington, Obama said that the American nation is facing real danger and warned Congress of "catastrophe" if it did not pass his stimulus plan this week. Obama piled more pressure on lawmakers to complete a long political tug-of-war over the 800-billion-dollar-plus package, with the once mighty US economy suffocated by staggering job losses and mired in a credit crunch. "That is a deficit that could turn a crisis into a catastrophe, and I refuse to let that happen."