A Senate report on the 2009 massacre at Fort Hood criticizes the FBI for failing to see warning signs that the shooting suspect was a "ticking time bomb" who's actions could've been avoided.

The report found that the Defense Department and FBI had enough information to detect that Army Maj. Nidal Malik Hasan had become an Islamist extremist, but failed to act on it.

Sen. Joseph Lieberman, I-Conn., chairman of the Senate Homeland Security and Governmental Affairs Committee, and its ranking Republican, Sen. Susan Collins of Maine released their finings, Thursday.

"Our report's painful conclusion is that the Fort Hood massacre could have, and should have, been prevented," Lieberman said, calling the situation a heartbreaking tragedy of errors.

Hasan was charged with 13 counts of murder and 32 counts of attempted murder in the November 2009 shooting rampage.

The Senate report also stressed that the FBI's move to become more "intelligence-driven" has been hampered by internal issues that must be addressed.

The FBI said in a statement it agrees with much of the report and had already identified some of the same concerns.

Army spokesman Col. Tom Collins also said the Army will "closely examine the report's findings and recommendations."