A U.S. Army Black Hawk helicopter had a close call on Thursday in Bucharest. Although the cause of the incident is still unknown, the helicopter was forced to make an emergency landing in Romania’s capital city, Bucharest, shutting down nearby traffic.

Videos show the helicopter participating in a formation flight that officials say was being flown as training for an air show on Romanian Air Force Day that will take place on July 20-21. The helicopter then suddenly loses altitude and the pilot is forced to land it on a roundabout, bringing down light poles and tree branches in the process.

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Fortunately, although there were cars on the street, no injuries are reported because of this incident. A military prosecutor arrived at the site to investigate the cause of the emergency landing.

The U.S. Embassy in Bucharest wrote on Facebook that the event took place at around 10:00 am local time and that the helicopter was moved to one side of the road to allow traffic through as authorities conducted their investigations.

The Romanian Defense Ministry, meanwhile, has canceled all aircraft participation in two scheduled ceremonies being held for the event.

“Both ceremonies will be held, but no military aircraft will participate,” Brigadier General Constantine Spinu, a Defense Ministry spokesperson, told Reuters.