President Obama turned a question on Libya into an attack on Romney for criticizing his adminsitration's response to the attacks, saying the US needed to come together.
"Nobody is more concerned about their security and safety than I am," Obama said of the diplomats abroad.
Romney criticized Obama for fundraising in the wake of the attacks and repeated his oft-discredited suggestion that Obama embarked on an "apology tour" when he took office.
Obama said he vowed to "hunt down" those who commited the crime the day after the attacks and greeted the caskets returning.
"The suggestion that anybody on my team would play politics or mislead when we've lost four of our own, governor, is offensive," Obama said.
Then the two clashed on whether, when and where Obama had called the attacks a terror event. He said it was a day later in the Rose Garden, Romney challenged him -- but moderator Candy Crowley backed Obama's version.
Obama didn't outright call the deaths a terrorist attack, but did say that "no acts of terror will ever shake the resolve of this great nation, alter that character, or eclipse the light of the values that we stand for."