Richard Rosenthal told the Los Angeles Times Andrews died of natural causes.
Patricia Marie Andrews was 14 when she began singing professionally with her sisters, LaVerne and Maxene, in 1932. The Andrews Sisters' first major hit record -- "Bei Mir Bist du Schon" -- went to No. 1 in 1938, and the trio eventually had 19 gold records, dozens of Top 10 hits and total record sales of nearly 100 million from 1938 to 1951.
Their hits included "Boogie Woogie Bugle Boy," "Rum and Coca Cola," "I'll Be With You in Apple Blossom Time," "Don't Sit Under the Apple Tree," "Beer Barrel Polka," "Beat Me Daddy, Eight to the Bar" and "I Can Dream, Can't I?"
Patty Andrews was born Feb. 16, 1918, in Mound, Minn. She and her sisters left school and began singing professionally after their father's business failed.
Her first marriage, to agent Martin Melcher, ended in divorce in 1950. She married Walter Weschler, the trio's conductor and arranger, who died in 2010.
Patty Andrews had no immediate survivors, the Times said. Maxene Andrews died in 1995. LaVerne Andrews died in 1967.