WASHINGTON

Authorities in the US state of Nevada responded on Tuesday after an explosion and fire were reported at the historic Hoover Dam.

The Boulder City Fire Department said it responded to an "emergency call" at the 720-foot (219 meter) dam. It added in a follow-on tweet that the fire was extinguished before the department arrived on the scene.

Bystander video from the site appeared to depict a large fire at the base of the dam with a thick black plume of smoke drifting into the air.