"The number of collapsed buildings this time is less, and most are old houses that were built long before, " added Wang Ruheng, dean of the school of civil engineering and architecture at Southwest University of Science and Technology in the city of Mianyang, in Sichuan province.

WSJ: After China Quake, Efforts Turn to Recovery

Researchers at the Massachusetts Institute of Technology's Civil and Environmental Engineering department looked at the 40 largest U.S. airports and figured out which ones would be the most likely to spread a disease in the event of an outbreak in the cities they serve.

CNN: Researchers list top 10 airports for spreading disease