Official: 18 firefighters dead in Arizona

(CNN) -- Eighteen firefighters battling a blaze in Arizona who were unaccounted for Sunday night have been confirmed dead, said Wade Ward with the Prescott Fire Department.

All were members of that city's fire department. It was not immediately clear how they died.

Earlier, an official with the Arizona State Forestry Division had said that as many as 19 were still missing.

The crew was fighting the Yarnell Hill fire, which broke out Friday northwest of Phoenix. The fire has grown to 1,000 acres, damaged three homes and forced the evacuations of residents in the communities of Peeples and Yarnell, forestry official Art Morrison said.