"What would happen to our own economy in such an event?"
The more relevant question is "what would happen to China's economy if it occurred?" We can operate comfortably without China while China would collapse without us. Over half of their exports go to America and our allies. While only 13% of our total imports are Chinese.
China Export Partners:(2004)
US 22.8%, Hong Kong 16.2%, Japan 12.4%, South Korea 4.4%
http://www.cia.gov
How long would it take to shift that 13% to other countries, or somehow bring that manufacturing home again (very unlikely considering the cost of doing business here)? I'm still thinking that the shock to our own economy would be significant.