LOUISVILLE, Ky. (AP) — Firefighters in Kentucky’s largest city were working to rescue a person trapped under debris Thursday at a construction site near downtown.

Louisville fire officials say a construction worker fell into a gap and some debris fell on top of him just before noon Thursday. The worker is talking to rescuers but can’t move, Louisville Fire Chief Brian O’Neill said. The worker is about 10 to 12 feet (3 to 3.7 meters) underground, O’Neill said.

Six other workers were on the scene when the man fell. They were working on the site of a former correctional building that is being demolished to make way for a medical campus.

O’Neill said firefighters were on the scene within three minutes and began performing a ditch rescue. Workers will try to clean debris from around the man’s arms and chest so he can receive medical attention, the chief said.

The rescue could take hours, O’Neill said.

“This is a very, very slow process,” he said.

Earlier this week, just a few miles away, a Louisville manufacturing plant exploded, killing two workers and destroying dozens of nearby homes. The cause of the explosion is not yet known.