A routine Fourth of July arrival turned into an unusual aviation incident after a Delta Air Lines aircraft was apparently struck by a firework while descending into Chicago Midway International Airport.

According to newly released air traffic control audio, the pilots of Delta Flight 1076 radioed the tower moments before landing, saying, “We just had a firework hit our plane.” The crew reported feeling a significant impact at approximately 200 feet above the ground, adding that they hoped it was “just a mortar that went off underneath.”

Controllers responded that they had received multiple reports of similar incidents that evening and instructed the aircraft to continue to the gate for a full inspection. As another aircraft approached Midway, controllers issued a stark warning: “Welcome to the war zone,” prompting a Southwest Airlines pilot to reply, “That’s reassuring.”

The Chicago Police Department later confirmed the aircraft sustained only minor paint damage, and fortunately, no passengers or crew members were injured. The aircraft landed safely around 8:30 p.m. local time on July 4 and returned to service the following morning after inspections.

The Federal Aviation Administration is investigating the incident to determine exactly how the firework came into contact with the aircraft. Consumer fireworks can reach altitudes of up to 200 feet—roughly the same altitude reported by the Delta crew during the final moments of their approach—raising concerns about the risks posed by fireworks near airport flight paths.