The Pentagon says 349 U.S. servicemen and women killed themselves last year, more than the number of troops killed in combat.

The number is up from the 301 military suicides in 2011. Some experts predict the number will be even higher this year.

Defense Secretary Leon Panetta has called suicides in the armed forces an epidemic, but a trend the Penatagon seems unable to control or fully understand.

U.S. military leaders have made suicide prevention one of their highest priorities. Experts put some of the blame on stress and alcohol. They also say many soldiers, sailors and Marines face uncertain futures after the end of the war in Iraq and next year's expected withdrawal from Afghanistan.