Split Rock (also Splitrock) is a hamlet in the Town of Onondaga in Onondaga County, New York, United States. Today more a historic place than a community, Split Rock is a site of interest to industrial archeology. The Solvay Process Company developed quarry operations here, delivering limestone used for the Solvay process by a remarkable elevated conveyor to the industrial plant at Solvay, New York. During World War I, Split Rock was the site of a munitions factory which exploded on July 2, 1918, killing at least 50. Following the war the site ceased production of war materials, but was used for a time as a State Department of Transportation maintenance and parking facility supporting DOT operations in the Central New York area. That role ceased in the mid-1980s. Today the area has largely reverted to natural growth, but retains ruins, including man-made tunnels as well as natural limestone caves.
The explosion of July 2, 1918 allegedly occurred after a mixing motor in the main TNT building overheated. The fire rapidly spread through the wooden structure of the main factory. Firefighting efforts were hampered by a loss of water pressure, and the factory eventually exploded. Approximately 1-3 tons of TNT were involved in the blast, which leveled the structure and led to the death of 50 men (conflicting reports mention 52 deaths). Other factory buildings on the site were largely unaffected, and the production of picric acid, nitric acid, and other products continued throughout the remainder of the war.
Large quantities of TNT and picric acid awaiting shipment were stored in magazines and warehouses across a valley from the main factory. However, the fire did not spread to these.
Split Rock High School was built in 1918 and served the community until 1950, when it merged with the Camillus, Fairmount, and Warners school districts to form the West Genesee School District. Split Rock then became an elementary school within that district.