Given that because of the various circuit breakers and regulations in place, it's rather hard to completely shear the elevator cables of the financial system and send the world economy plummeting into the basement as happened in 1929.
However, what if the deadly H5N1 strain of Avian Influenza mutates in such a way as to make human to human transmission possible at nearly the same time as the Lehman Brothers collapse. Let's say the initial outbreak of the new strain starts in.....China somewhere, perhaps in rural Guangdong province relatively close to Hong Kong and Guangzhou.
However, what if the deadly H5N1 strain of Avian Influenza mutates in such a way as to make human to human transmission possible at nearly the same time as the Lehman Brothers collapse. Let's say the initial outbreak of the new strain starts in.....China somewhere, perhaps in rural Guangdong province relatively close to Hong Kong and Guangzhou.