Crews went through a manhole to rescue a woman who was found trapped in a storm drain in Southern California several days after she was reported missing, officials said.

       Yafang Zhou, 59, was reported missing on April 3, according to San Diego police. She hadn't been seen since March 25, police said.

       On Monday, officials searching for her by a hiking trail in Poway "heard a woman’s voice coming from the area of a maintenance hole cover," police said.

       Firefighters, paramedics and search-and-rescue teams rushed to the scene and rescued Zhou, who was 8 to 10 feet below ground, Poway Deputy Fire Chief Chuy Ramirez said.

       She was hospitalized in serious condition, police said.

       Zhou's location was pinpointed by firefighters' "good, old fashioned sleuthing," San Diego Fire Department Battalion Chief Erik Windsor told reporters.

       He said the firefighters removed each 100-pound manhole cover in the area "and just [kept] going until they could either hear her or see her."

       "They looked down inside underneath that manhole cover, and that's where they saw her," he said.

       Windsor said it's not clear how Zhou got inside the storm drain.

       "There were no removed manhole covers when our crews got here," he said. "It is possible that she entered into the storm drain system from one of the outlets, which would naturally be open where water would flow out into the creek, or some other way."