Elsie E. Green, 96, a teacher and principal in the D.C. public school system for 49 years and who was a founder of the Safety Patrol program, died of cardiac arrest Tuesday at the Baptist Home of the District of Columbia.

Miss Green, who was born in Washington and who maintained her own residence in the city until moving to the Baptist Home about eight months ago, graduated from George Washington University. She began her career with the public school system in 1906.

In 1928, when she was teaching at the Grant School, she organized the first Safety Patrol in the D.C. school system, winning the top prize of $600 in a national contest for teaching safety to children. Two years later, the American Automobile Association took up the idea and sponsored it nationally.

In 1952, the AAA cited Miss Green for her contributions to reducing traffic fatalities and injuries among youngsters. Her safety work also received recognition from the U.S. Chamber of Commerce and the Daughters of the American Revolution.

By that time, Miss Green was near retirement. She left the system in 1955, having spent the final 23 years of her service as principal of the Whittier Elementary School.

She then became president of the D.C. Retired Teachers Association and worked for increased benefits for its members. On several occasions she testified before congressional committees.

Survivors include a brother, Erman Patrick of Fort Lauderdale, Fla.