EAST WENATCHEE, Wash. (AP) — An 18-year-old in Washington state has been arrested for the investigation of manslaughter and arson in connection with a deadly July 4 fire, a county sheriff said Thursday.

The teen from Kent was among a group of people setting off illegal fireworks from the back of a truck when one landed in roadside brush, igniting the fast-moving blaze, Douglas County Sheriff Tyler Caille said. He said authorities were also seeking arrest warrants for five others.

The Chelan Hills Fire burned roughly 15.6 square miles (40.4 square kilometers), destroyed more than 100 structures, including 19 homes, and left one person dead, he said.

The victim was identified earlier this week as Robert Lister, a 69-year-old Orondo resident, whose vehicle had slid off the road and was consumed by the flames.

In a statement read aloud by a detective during a news conference Thursday, Lister’s family said the arrest allows them to begin healing.

“Rob’s life was taken far too soon, and he will continue to be loved, missed and remembered by all,” the statement read.

Caille urged the others accused of launching illegal fireworks to turn themselves in, or “we will come find you.” He said all are over 18 and are “complicit with the same crimes.”

“This is complete recklessness that led to billions of dollars of loss, loss of Mr. Lister’s life and, unfortunately, everybody involved in that is going to have to pay those consequences,” Caille said during the news conference.

Washington has had a severe fire season, with blazes scorching more than 1,125 square miles (2,914 square kilometers) across the state.

Another man was charged last month with starting the Old Trails Fire in Spokane, one of three fires in the area that burned more than 850 buildings and destroyed whole neighborhoods. He is also charged in connection with four smaller fires ignited in the summer of 2025 and last month.