More than 75 police officers and fire fighters are searching Whitpain Township Police today for a missing 14-year-old girl.

They are also seeking the man last seen with her.

Police Chief Mark A. Smith described that man, Mark O'Donnell, 48, as a "person of interest," and said investigators want to question him further about the disappearance of Ebony Nicole Dorsey, a freshman at Wissahickon High School.

The teen was last seen by her mother at 10:30 p.m. Thursday when the girl left with O'Donnell to baby-sit for his 4-year-old daughter, Smith said. The girl did not show up at school on Friday, but was not reported missing by her mother until Friday evening, Smith said.

He said the girl's mother, Danielle Cattie, did not know whether her daughter had returned home during that time.

Smith said the last call made to the girl's cell phone was from her father, Evan Dorsey, at 7 a.m. on Friday morning. The father calls his daughter every day at that time, Smith said. The call was routed to a tower on Jolly Road in Whitpain, midway between O'Donnell's residence and the girl's Ambler home, Smith said. That indicates the girl's phone was in the area, Smith said.

The police and firefighters are searching around the Jolly Road area this afternoon.

An investigator spoke briefly with O'Donnell early Saturday morning; however, police have been unable to contact him again, Smith said. At that time, he told officers he had driven the girl home at 6 a.m. Friday.

"He's sure not making himself available," said Smith.

O'Donnell's daughter is being cared for by O'Donnell's wife, who lives with him, Smith said. He described both her and Dorsey's mother as being "cooperative" with investigators.

Smith said state police said an Amber Alert - a system for notifying the public about missing children - has not been issued because police know the identity of the last adult seen with the girl.

Anyone with information is being asked to contact police at 610-279-9033. The girl is described as 5 feet, two inches tall and about 110 pounds. She was last seen wearing a pink top, white pajama pants, and a tan jacket with fur around the hood.

Contact staff writer Kathleen Brady Shea at 610-701-7625 or kbrady@phillynews.com.