The FBI has taken charge of the investigation into a fire that damaged equipment at an Enbridge drill site on the Line 5 reroute in northern Wisconsin, according to Wisconsin Public Radio.

The incident occurred at a horizontal directional drilling (HDD) spread on the segment of the 645-mile Line 5 system that Enbridge is building to reroute the pipeline around the Bad River Band of Lake Superior Chippewa reservation. The fire destroyed drilling equipment at the site. No injuries were reported, WPR said.

The FBI is leading the probe, working alongside local law enforcement. As of the WPR report, investigators had not released a determination on the fire's cause. The bureau has not said publicly whether it suspects arson, equipment failure, or another origin for the blaze.

Enbridge confirmed the fire hit a contractor's drilling rig working on the reroute. The Canadian midstream operator did not give an estimate of schedule impact in the WPR account.

Line 5 carries light crude oil and natural gas liquids from Superior, Wisconsin, across Michigan's Upper Peninsula and the Straits of Mackinac to Sarnia, Ontario. The roughly 41-mile Wisconsin reroute moves the line off reservation land after years of litigation between Enbridge and the Bad River Band. A federal judge in 2022 ordered the pipeline off the reservation, and the parties subsequently agreed on a reroute corridor.

The fire is the latest in a string of incidents tied to the pipeline. In June 2025, a device exploded at a Line 5 valve site in Michigan — an attack for which a Wisconsin man now faces federal charges. The FBI investigated that incident as well.

Construction progress and timing on the reroute will be the immediate watch item: Enbridge has targeted completion of the Wisconsin segment in 2025, and any HDD setback at this stage carries the risk of pushing the in-service date. The FBI's determination on the fire's cause is the other open question for operators tracking physical and security risk along the Great Lakes corridor.