Eleven people became sick Tuesday after a suspicious envelope was opened in a building at Joint Base Myer-Henderson Hall in Arlington, Virginia, authorities said. Three of those who fell ill were taken to a local hospital, where they are reportedly in stable condition. “Base officials are coordinating with local haz-mat teams and FBI. Several Marines are receiving medical care as a result of this incident,” Maj. Brian Block, a U.S. Marine Corps spokesperson, told reporters. A corporal, a gunnery sergeant, and a colonel were reportedly among those affected, with symptoms of a burning sensation on their hands and face. Another person suffered a nosebleed, according to CNN. The letter was addressed to a commander at the base and contained a rant full of derogatory remarks and at times incoherent language, a law-enforcement official told CNN. Field tests came back negative for any harmful substances, but the FBI lab in Quantico is expected to conduct further analysis.