(Washington, DC) -- Army Chief of Staff General George Casey is concerned about a backlash against Muslim troops in the aftermath of the massacre at Fort Hood, Texas, last week. Appearing on CNNs "State of the Union," Casey said, "it would be a shame if our diversity became a casualty as well." He said hes asked Army leaders to be on the lookout for discrimination against Muslim soldiers. Discussing Major Nidal Hasan, whos accused of killing 13 people and wounding dozens of others, Casey cautioned against jumping to conclusions before all the facts are determined by investigators. Independent Senator Joe Lieberman appeared on "Fox News Sunday," calling the Fort Hood killings, "the most destructive terrorist act to be committed on American soil since 9-11." On another program, NBCs "Meet the Press," General Casey said, in his words, "its way too soon to be drawing any conclusions about what happened or what (Hasans) motivations were." Both the military and the Justice Department are investigating the shootings.