TUCSON, Ariz. -- A Tucson firefighter refused to respond to a 911 call to the Jan. 8 shooting spree that left six people dead and 14 injured, including Arizona Rep. Gabrielle Giffords, the Arizona Daily Star reported Thursday.

Mark Ekstrum, who was part of a team trained to deal with major emergencies, quit the force two days later as management was investigating possible disciplinary action against him.

According to a memo obtained by the Daily Star, Tucson Fire Department Capt. Ben Williams said Ekstrum told him he would not go on the call.

"He mentioned something about 'political bantering' and he did not want to be part of it," the memo stated.

Williams wrote that Ekstrum "started to say something about how he had a much different political viewpoint than the rest of the crew and he was concerned."

Ekstrum then informed Williams he was going home sick and the crew attended the scene without him.

The shooting took place at a political event hosted by Giffords (D-Ariz.).

The congresswoman was shot in the head at point-blank range and is currently undergoing rehabilitation at a facility in Houston. The accused gunman, Jared Lee Loughner, is before the courts.