A New York City teacher missing since last month was saved by a ferry captain Tuesday after she jumped into the harbor in an apparent suicide attempt.

Hannah Upp, 23, was in stable condition after the dramatic midday rescue in New York Harbor by the crew of a Staten Island ferry.

Police say she jumped from a pier in Staten Island. A captain en route from Manhattan spotted her.

"The story I hear was that the ferry crew observed a female in the water, deployed a rescue craft and brought the female victim to St. George ferry terminal" in Staten Island, NYPD Officer Martin Brown told FOXNews.com.

Brown declined to offer details about Upp's mental state or physical condition or confirm that she was trying to take her life, saying those details were unknown and an investigation was under way.

The young teacher, who had a pulse but wasn't conscious when she was brought onto the boat, was taken to Richmond Hospital in Staten Island, according to a Department of Transportation spokeswoman.

Brown confirmed that her injuries weren't life threatening.

"She's not likely to die," Brown told FOXNews.com.

She was wearing a black athletic tank top and red shorts with no shoes, according to DOT Executive Director of Safety and Security Margaret Gordon.

Upp was last seen Aug. 29 after disappearing from her Manhattan apartment days before classes started at Thurgood Marshall Academy.

Brown said it wasn't yet clear why she vanished. The NYPD plan to interview Upp as part of their investigation.

Upp's family and friends launched a massive search. Her credit cards and personal belongings were found in her apartment.

Police say she was apparently spotted at least twice in various locations around the city, including at an Apple store, where she was seen using a computer to check e-mail.

Click here for more on the story from MyFOXNY.com.

FOXNews.com's Catherine Donaldson-Evans, Jana Winter and The Associated Press contributed to this report.