Complex sentence: Many of Colleen Moore's films deteriorated but not due to her own neglect, sending them to be preserved at the Museum of Modern Art. Some time later, Warner Brothers asked for their nitrate materials to be returned to them.
Split into simpler sentences: Many of Colleen Moore's films deteriorated but not due to her own neglect. She actually sent them to be preserved at the Museum of Modern Art. Some time later, Warner Brothers asked for their nitrate materials to be returned to them.