NEWRY – Insurance company investigators have tentatively identified failure of the grout that locks steel supports in place as the cause of a chairlift failure at Maine’s Sunday River this month.

Sunday River spokeswoman Darcy Lambert announced the tentative findings Wednesday and said MountainGuard engineers are returning Thursday to take samples.

The top unloading terminal of Sunday River’s Spruce Peak Triple lift toppled over when the foundation separated from the mountaintop. No one was hurt because it happened during the summer when the lift was not in operation.

Photos released after failure suggested that reinforced steel bars, or rebar, had separated from mountaintop. The steel rebar is inserted into holes drilled into the mountaintop and is held in place by grout.