The Pemberton Mill was a large factory in Lawrence, Massachusetts. It suddenly collapsed and occupants were crushed or burned alive on January 10, 1860, in what has been called "the worst industrial accident in Massachusetts history" and "one of the worst industrial calamities in American history". An estimated 88 to 145 workers were killed and 166 injured. Investigators attributed the disaster to substandard construction that was then drastically overloaded with second-floor equipment, all evident and preventable. The event was cited in improvements to industrial construction and workplace safety. The mill was soon rebuilt in place. Background The Pemberton Mill was built in 1853 as a five-story building long and wide. Its chief engineer was Charles H. Bigelow. Its construction was financed by John A. Lowell and his brother-in-law J. Pickering Putnam at a cost of . This was called "a fortune for those times". During a financial panic in 1857, Lowell and Putnam sold the mill to George Howe and David Nevins, Sr. at a $350,000 loss. The new owners jammed more machinery into their factory attempting to boost its profits. The mill ran with great success, earning per year, and had 2,700 spindles and 700 looms in operation at the time of the disaster. Collapse Shortly before 5:00 p.m. on a Tuesday afternoon in 1860, workers in nearby factories watched with horror as the Pemberton Mill buckled and then collapsed with a mighty crash. According to later court testimony reported by The New York Times, owner George Howe escaped as the structure was falling. Dozens were killed instantly and more than six hundred workers, many of them women and children, were trapped in the twisted ruins. When the winter sun set, rescuers built bonfires to illuminate their efforts, revealing "faces crushed beyond recognition, open wounds in which the bones showed through a paste of dried blood, brick dust, and shredded clothing". Around 9:30 p.m., with many people still trapped in the twisted wreck of the factory, someone accidentally knocked over an oil lantern. Flames raced across the cotton waste and splintered wood — some of it soaked with oil. One trapped man cut his own throat rather than be consumed by the approaching flames; he was rescued, but died from his other injuries. As the fire grew, rescuers, physicians, families of the trapped victims, and spectators were all driven back by the conflagration. The screams coming from the ruins