Paul G. Vallas, who has led some of the nation's most troubled school systems, has been appointed interim superintendent of the Bridgeport (Conn.) school district. Vallas, 58, inherits a $6 million budget gap and is answering to a state-appointed school board.

Vallas was city budget official in Chicago before he was tapped to run the Chicago public school system. After his stint in Chicago, he moved on to lead the Philadelphia school system. After Hurricane Katrina in 2005, he led the Recovery School District in Louisiana that was responsible for many of the public schools in New Orleans.