The employee, Dariel Vasquez, was killed while fighting a fire in Sterling Forest in Greenwood Lake, N.Y., the New York State Police said in a statement late Saturday. Steve Neuhaus, the Orange County executive, said that Mr. Vasquez was helping to clear trees and shrubs, which are fuel for a fire, from a wooded area when a tree fell and hit him.

Fire crews on both coasts of the United States continued battling wildfires on Sunday, including a blaze in New York and New Jersey that killed a parks employee and another in Southern California that destroyed more than 130 structures and damaged dozens more.