It was short, but sweet.

In 2009, at age 40, William J. Gretzula was appointed superintendent of Bucks County's Bensalem School District.

Wednesday night, citing family priorities and the wish to return to his roots as an educator, the now 42-year old Gretzula announced to the astonishment of residents at a school board meeting that he was leaving the post to teach in the district's schools.

The board hired him as a teacher on the spot; what school, grade, and subject he will teach have yet to be determined. He will stay on as superintendent until the end of August, Gretzula said in an interview Thursday.

By all accounts, the decision to step down was Gretzula's and he will be missed. "He has been a godsend," school board vice president Harry R. Kramer said. "He is one of those people who has a remarkable insight into the needs of kids. I'd say he has been our best superintendent in the last 25 years. He has that gleam in his eyes. He just lights up when he talks about education. He will be hard to replace."

Gretzula, who came to the 6,000-student Bensalem district in 2007 as an assistant superintendent and whose salary is now $159,500, said in an interview that he had already missed too many singular moments with his children, who are 8 and 5.

That was brought home, he said, when his son told him recently that he loved and hated his dad's job.

"Everywhere you go, people know you," his son had told him with pride. But he added, "you are not home a lot."

Gretzula said he realized he had been "everywhere except where I am supposed to be - with my family."

He noted that as a teacher, he will still devote a great deal of time to his job, but said he will have more flexibility than he has now.

"I need to be more available for my family," he said.

Gretzula said he was also leaving the top job because teaching is where his heart lies.

"I want to reconnect to the passion that got me into this in the first place," he said. "It's about getting back to the heart of the matter: teaching and learning."

Gretzula said he believed he was leaving the district in good shape and with a capable school board overseeing it. He fears, however, what the future will bring because, he said, "public education is under attack" by the push toward charter schools and funding cuts in the legislature.

He said that rather than focusing on improving education for children, his colleagues are beginning to talk about "dismantling public education with care."

"I don't want to spend the next 20 years taking apart public education brick by brick," he said. "I'm not going to sit here and do that."

Contact staff writer Dan Hardy at 215-854-2612 or dhardy@phillynews.com.