ST. LOUIS, July 17 (UPI) -- The Gateway Arch and Museum in St. Louis was evacuated and closed Thursday after a transformer caught fire, sending thick black smoke through the monument.
KMOV reported the thick black smoke could be seen for miles after witnesses said they heard a series of explosions in an underground transformer vault shortly before noon.
No injuries occurred, although numerous emergency vehicles and personnel were sent to the scene.
KSDK said FBI agents and police detectives were dispatched to the scene as a precautionary measure until it was determined the incident was not terrorism related.
Officials said the Arch would be closed for at least two days while repairs are made.