PHOENIX -- Several hikers may have started the fire that scorched 5,300 acres near Crown King, authorities said.

Phoenix resident Angela Tarango, 32, contacted the Yavapai County Sheriff's Office on Saturday to report that her boyfriend Jeffery Rasmussen, 46, and her two children, ages 11 and 9, had not returned from a morning hike.

Another hiker, David Cygan, 49, agreed to assist Tarango and her 14-year-old son with the search.

Cygan and the 14-year-old eventually found the group, and Cygan left to find a way back to camp. Deputies had already called for a helicopter to search the area.

At around 9 p.m. rescue personnel notified deputies of a fire in the search area. The air search was called off due to the darkness, but more rescue troops were deployed on the ground.

At some point during the night, another fire was reported in the area.

Search and rescue located Tarango's family at around daybreak; Cygan was found around 7 a.m. By this time, the fire surrounding the group was out of control.

A helicopter arrived, met the rescuers and the missing hiker and flew the group to safety.

According to officials, at least two fires were seen during the search. Rescue team leaders have initially classified the fires as "warming fires," though the specific purpose is unknown.

The U.S. Forest Service is currently investigating the cause and the perpetrators of the fires. Its findings will be submitted to the U.S. Attorney's Office.