BANGOR (AP) – Railroad officials are investigating what caused rail cars carrying rolls of paper to go off their tracks and fall into the Penobscot River.

The accident happened at about 11:30 a.m. Sunday near the intersection of Hogan and State streets as a train made its way from Old Town to Hermon carrying large rolls of paper from the Georgia-Pacific mill, which shut down March 16.

Two rail cars tumbled down an embankment and into the river, while a third car came to rest on its side on the riverbank. Nobody was hurt, officials said.

Two engines and 10 of the 18 cars continued on to Hermon later in the afternoon, said Sgt. Tim Falvey of the railroad police.

Officials said it could be a couple of days before they can get the track repaired and pull the boxcars out of the river.

There was no official cause on the accident, but the ground under the tracks appeared to have given way toward the river.