The Tribune Company is the parent organization of the Chicago Cubs and the Chicago Tribune. Daley said Tuesday that the mistakes include the newspaper's coverage of the story.
Tribune editor Ann Marie Lipinski says the newspaper's stories have been complete and tough.
Chunks of concrete have fallen from the ballpark's upper deck on at least three occasions since June. Stadium officials installed nets to protect fans.
Last week the city released a 2001 engineers' report on Wrigley's condition. Cubs officials say repairs were made without the required city permits.
Buildings Department spokesman Jack Beary says officials will determine what work was done without permits and possible penalties.