Community and education leaders urged support of a $12.3 billion statewide school-bond measure Thursday in Fresno, saying California schools and colleges are overcrowded and in disrepair.

The measure, placed on the March 2 ballot by the Legislature, would allow the state to sell $10 billion in bonds to build new schools and renovate older ones and $2.3 billion in bonds for projects at community colleges and four-year universities.

Officials at a news conference at Lincoln Elementary School said that:

One million children attend schools with broken bathrooms.

California has the third-most-crowded classrooms in the nation.

Many schools have leaking roofs and no heating and cooling systems.

"We can't expect our children to learn in these kind of conditions," said Sherry Wood, president of the Fresno Teachers Association.

School districts across the state are depending on the passage of Proposition 55 to provide matching funds for numerous projects.

In the Fresno Unified School District, officials would have to scrap plans to modernize 42 schools and could not build four of the 10 elementary schools scheduled for construction if Prop. 55 does not pass, said Chuck McAlexander, director of operational services.

California State University, Fresno, is depending on Prop. 55 for $85 million to renovate and expand the Henry Madden Library, the largest research library between Sacramento and Los Angeles. The library was built to serve 13,000 full-time students; more than 20,000 students attend Fresno State.

Other projects that need Prop. 55 funding include:

In Fresno Unified, construction of six library/media centers and two cafeterias; renovations at Lincoln, Bullard High School, Addams Elementary School, Ahwahnee Middle School, Burroughs Elementary School and Malloch Elementary School.

In Clovis Unified, construction of an intermediate school, high school and elementary school; and renovations at Temperance-Kutner Elementary School and Kastner Intermediate School.

In the State Center Community College District, renovations at Fresno City College and new buildings at the proposed Willow International Center.

A broad-based coalition of supporters is aggressively campaigning for the passage of the proposition, saying it is essential for the state's education system and that it will generate new jobs and improve the economy.