Three empty train cars that had been used to carry canola oil derailed Saturday in Aberdeen and have since been cleared from the tracks, but there’s still no indication of what caused it. The incident is still under investigation.

Three middle tank cars derailed, with the middle one falling perpendicular to the tracks while the two others remained partially on two different forks of the track separated by about 20 feet. The incident took place near the end of South Alder and State streets, around noon according to one railroad worker at the cleanup Sunday.

The train cars were previously filled with canola oil, but were empty at the time, according to spokesperson Michael Williams from Genesee & Wyoming Railroad Services, which owns the Puget Sound & Pacific Railroad. He said the train was being picked up from and delivered to local industries, but didn’t specify which. There were no injuries or “hazardous materials” involved, and an investigation is ongoing, Williams added.

The Renewable Energy Group biodiesel plant in Hoquiam has used canola oil in its process to produce fuel. The company didn’t respond to a request for comment.

Many local residents complained on social media over the weekend, saying derailments have been an issue in recent years on the Harbor and asking more be done to keep the tracks in good condition.

Joshua Francy, an Aberdeen resident who runs the “Clean Streams and Memes” volunteer team that regularly cleans up the watershed area around Grays Harbor’s residential areas, called for a need to improve the railroad’s overall safety and attention to maintenance.

“There have been more than five train derailments and accidents in the area in the last half decade,” said Francy, who is running for Aberdeen City Council in the upcoming election. “… It does seem to indicate a lack of railroad safety protocols.”

Railroad workers were on the scene Sunday morning, and used a crane to lift the most displaced car back onto the tracks. Several of the workers could be seen working on and checking the railroad switch, where the track diverges into two forks. As the train track heads east from the site of the derailment, the track splits into many more branches before converging back to one where it passes South H Street.

There is so far no federal investigation of the derailment from the National Transportation Safety Board, according to Public Affairs Officer Keith Holloway. He added that factors such as there being fatalities, or if there was risk to the environment like a leak in a car, can affect whether it warrants a federal investigation.