CHICAGO -- Angry parents in a tough South Side neighborhood kept nearly half the pupils home from a public school yesterday after the principal demoted 250 youngsters at midyear because of poor reading skills.

"I will never agree to demoting my child," said Brenda Wimberly, whose son, Dontae, 9, was demoted from third to second grade. "If his reading doesn't come up in April, then he can remain in the third grade for next year."

About half of Beethoven Elementary School's 830 students have been kept out of the school since Monday by angry parents.

"I took the step because my children were so far behind -- two, three, four years behind in reading -- that we had to do something," Principal Grace Dawson said of the results of achievement tests in her school. "We had to take a stand that children can't just sit in the classroom and do nothing." Demoted students were not shifted to other classrooms, but were given materials from lower grades, Dawson said.

Most of Beethoven's students live in the nearby Robert Taylor Homes, the nation's largest high-rise public housing project. It stands in one of the city's poorest South Side neighborhoods, an area rife with crime and street gangs.