President Obama gave an ad hoc speech about Thursday's mass shooting at Fort Hood during an appearance at the Department of the Interior's Tribal Nations Conference. The president's speech did not enumerate details beyond those already made public, but expressed sympathy and "thoughts and prayers" for those killed or wounded in the "horrific outburst of violence." Noting that he had already spoken to Defense Secretary Robert Gates and Chairman of the Joint Chiefs of Staff Admiral Mike Mullen, Obama said the Pentagon, FBI, and Department of Homeland Security were working to secure the base. "It's difficult enough when we lose these brave Americans in battles overseas," the president said. "It is horrifying that they should come under fire at an Army base on American soil."