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.

A New York parks employee died battling one of a number of wildfires in New Jersey and New York amid dry conditions that have prompted air quality warnings in both states, authorities said Sunday.