Works of Lewis Hine are in the middle of a his negatives. Lewis Hines produced pictures of the groundbreaking work for the National Child Labor Committee and the construction of the Empire State Building. Walter Rosenblum, a friend of Hine's, became the conservator of Hine's works and is now the focus of suspicion that he doctored photos. He has personally documented the authenticity of many of Hine's photographs, asserting that they were made in his presence, and brought them to dealers, including some in Chicago, for sale. Hine's "Mechanic and Steam Pump" was sold for $90,000 at a Christie's auction in 1994.