State police say a medical issue likely caused the driver of a fuel truck to lose control of the vehicle, which overturned along I-295 in South Portland Monday.

The truck had just left the South Portland fuel depot, and its entire load of 2,900 gallons of home heating oil spilled, the Maine Department of Public Safety said in a news release.

The release, sent out just after 2 p.m., said traffic was down to one lane for both north and southbound traffic. The lane closures were expected to continue throughout the afternoon and lead to major traffic delays.

The driver of the truck, Dale Brown, 58, of Topsham, was taken to Maine Medical Center in Portland for treatment of a head injury and his medical issue, suspected to be heart related. Both were believed to be non-life threatening.

Oil spilled onto the road, went into the median and flowed into a drain pipe into the Fore River. The Maine Department of Environmental Protection was contacted to clean up the oil spill. The agency was expected to remain on the scene throughout the afternoon.

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