Chattanoogans puzzle out answers, pour out grief day after deadly shooting spree

While heroes are mourned, the city looks for answers to Thursday's tragedy

Donna Christian-Lowe puts her hand to her face as people bow their heads in prayer during an interfaith vigil at Olivet Baptist Church held in remembrance of victims of the July, 16 shootings on Friday, July 17, 2015, in Chattanooga, Tenn. The vigil was held one day after gunman Mohammad Youssef Abdulazeez shot and killed four U.S. Marines and wounded two others and a Chattanooga police officer at the Naval Operational Support Center on Amnicola Highway shortly after firing into the Armed Forces Career Center on Lee Highway.

Chattanooga police officers took a "tremendous amount" of gunfire when they confronted Mohammad Youssef Abdulazeez at a military center on Amnicola Highway on Thursday, but officers continued to move forward and shoot back until Abdulazeez was killed in the firefight, according to the FBI.

Chattanooga Police Chief Fred Fletcher and others described the gun battle and ongoing investigation in a news conference Friday.

Abdulazeez opened fire with at least one AK-47, officials said, killing four U.S.