[UPDATE] Biden to attend Arizona firefighters memorial YARNELL, Ariz., July 6 (UPI) -- The White House said Vice President Joe Biden will attend next week's memorial service for 19 firefighters killed in an Arizona wildfire. An official whose name was not reported told NBC News Biden will be among the large crowd expected at the event Tuesday in Prescott. The Yarnell fire, which was 90 percent contained but still burning Saturday, shifted course and overran a Prescott fire crew June 30. The death toll was the largest single-event loss of life for U.S. firefighters since Sept. Firefighters said Saturday they have turned the tide on the Yarnell fire. Incident commanders said the weather was now in their their favor and the flames were creeping into an area where fuel was relatively sparse. Full containment, however, was estimated at a week away. The fire has burned about 8,400 acres. Some evacuations remained in effect. An investigation into how the Granite Mountain Hotshots wound up in a position to be overwhelmed by the fire June 30 was focused on the tactics and communications in place at the time. "These investigators, with 30 plus years of experience, are scientists," Jim Paxon, the leader of the investigation, told KPHO-TV, Phoenix, this week. They will try to discern what happened, and how can we prevent it in the future.