The steel frame reached street level in February 1914. The cornerstone was officially laid on April 30, 1914, at a ceremony attended by mayor John Purroy Mitchel. The Equitable Building was the first private construction project in New York City where the mayor attended the cornerstone-laying ceremony. Work on the superstructure officially began on June 10, 1914. By August 16, the structure had topped out at 38 stories above the ground level. Work on the building was completed on February 1, 1915.