Toxic chemical leak at Ohio explosives plant prompts no-fly zone, mass evacuations | 11 June 2025 | A massive chemical leak spewed toxic orange plumes of dangerous acid into the sky, forcing a no-fly zone and mass evacuations near an explosive plant in Ohio, according to reports. About 3,000 gallons of nitric acid was released from an enormous tank at the Austin Powder Red Diamond Plant in McArthur -- which manufactures explosives used for mining and construction -- around 8:30 a.m. Wednesday, a Vinton County spokesperson told WLWT. Spillage from the 5,000-gallon take caused officials to evacuate nearby roadways and the Village of Zaleski, home to about 750 residents, with a shelter set up at Vinton County High School for evacuees, the Vinton County Sheriff's Office said. The Federal Administration Authority also enforced a temporary 30-nautical-mile flight restriction around the hazardous site until Thursday, the outlet reported.