'Terrified' Rescue Dog Spent 2 Days In SF Caltrain Tunnel Before Being Found

SAN FRANCISCO, CA — A missing dog has been reunited with its owner after spending two days "scared and hunkered down" inside a Caltrain tunnel in San Francisco, animal control officials said.

The dog, "Roo," was recently adopted, but an incident where he got spooked prompted him to run off, according to Animal Care & Control San Francisco.

A train operator saw him on the first day, but they thought he was a dead animal, officials said.

Another train operator was going through the tunnel on the second day and saw the dog move, officials said.

"He was so still they thought he had been hit by a train and was injured," animal control officials said.

This prompted two officers to go into the dark tunnel, where moments later they encountered Roo, officials said.

"He was terrified at first, then was thrilled to be rescued," officials said, adding that he was not injured.

Roo turned out to be microchipped, and he was reunited with his "thrilled" owner, who was looking everywhere for him, officials said.