NBC 7 San Diego Rescue crews lower a firefighter into a well in Portrero, Calif., to rescue a man who had fallen inside.

SAN DIEGO -- Fire crews rushed to the Potrero community in San Diego’s Mountain Empire area Sunday afternoon to rescue a man who had fallen down a 35-foot well.

According to Cal Fire Capt. Mike Mohler, the victim fell down the 35-foot hole in the 1300 block of Potrero Circle at around 4:15 p.m. local time (7:15 p.m. ET). The fall knocked the man unconscious, Mohler said.

Rescue crews set up a tripod above the well and lowered a firefighter into the hole to rescue the 42-year-old man. He was pulled from the well at around 6:18 p.m. (9:18 p.m. ET), Mohler said.

An air ambulance transported the victim to a local trauma center. Mohler said the man's exact condition was not known, but he was likely in serious or moderate condition because of the length of the fall.

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At one point during the "confined space" rescue mission, Cal Fire crews had to drop a pump down into the well, fearing ground water would rise up and possibly drown the victim.

"That's always a concern in this type of rescue mission," Mohler said. "They had a lot of moisture down at the bottom of the well."

Mohler said the well had been boarded over and abandoned. The board snapped under the man's weight and he fell.

The victim was identified by his wife as Jerry Fowler of Potrero.