ASHLAND, Wis. — Authorities are investigating a fire that destroyed heavy machinery at an Enbridge Line 5 project site near Ashland, raising new concerns about security around the controversial pipeline project. The equipment fire was reported early Thursday, Sept. 17, at a drilling site in Ashland County. Investigators described the fire as suspicious and are examining whether it was intentionally set. The incident came days after a separate fire and threatening graffiti were discovered at an Enbridge building in Superior. The two sites are in northern Wisconsin, but police have not officially determined that the incidents are related. Enbridge condemned the destruction, calling those responsible “criminal saboteurs.” The company has not identified any suspects publicly. Line 5 is a major oil pipeline that crosses northern Wisconsin and runs through the Great Lakes region. Enbridge has sought to maintain and expand parts of the line, while environmental groups and tribal nations have opposed the project over concerns about spills, water resources and treaty rights. The investigation remains active. No injuries were reported in the available information, and authorities had not announced arrests or provided an estimate of the damage as of Sept. 18.