Daniel Gerson, the Monsters, Inc. screenwriter, has passed away. He died on Saturday at his home in Los Angeles after suffering from brain cancer, his family announced. Gerson was 49 years old.

Gerson made significant contributions to Disney/Pixar, often writing with Robert L. Baird. The pair wrote Monsters University and Oscar winner Big Hero 6 (along with Jordan Roberts). Gerson and Baird also worked on Chicken Little, Cars, Open Season, Meet the Robinsons, Up, and Inside Out.

He also provided the voices for janitors Needleman and Smitty in Monsters, Inc. and the desk sergeant in Big Hero 6.

Gerson was raised on the Upper West Side in New York City. He went to the Ethical culture Fieldston School in the Bronx, Cornell University, then film school at New York University where he earned a Master’s Degree. His film and TV career began in the late ’90 writing for Duckman: Private Dick/Family Man, Something So Right, and The New Addams Family.

Monsters, Inc. was a huge success in 2001, earning him a BAFTA Children’s Award in 2002.

He is survived by his wife Beau Stacom and children, Claire and Asher.