Iraq death toll: 655,000

They've been coming nearly every day, for more than three years. Reports of deaths in Iraq are sadly commonplace, even routine. They earn footnote mentions in news reports and it's thought that -- as in most cases of war -- the true number won't fully be known.

But a new report from Johns Hopkins University in the U.S. and Al Mustansiriya University in Baghdad has put forth a shocking number: 655,000 Iraqis dead since the invasion began in 2003. And the researchers say this amounts to a doubling of the usual mortality rate and the vast majority are the result of war-related conflict.

George W. Bush attacked the study, but didn't offer his own figures. The methodology is interesting. Researchers took a sample of more than 1,800 homes in locations across Iraq and asked them about deaths in their family.

They found gunshots the cause of half of the violent deaths, and one third are attributed to U.S.-led coalition attacks. Some 55,000 deaths were caused by illness, thought to be due to the deterioration of health care infrastructure.

The study was published in The Lancet, a highly-regarded medical journal in the UK.