LAKE MEAD NATIONAL RECREATION AREA, ARIZONA - JUNE 15: A visitor looks at the Hoover Dam on June 15, 2021 in the Lake Mead National Recreation Area, Arizona. Last week, The U.S. Bureau of Reclamation reported that Lake Mead, North America's largest artificial reservoir, dropped to 1,071.53 feet above sea level, the lowest it's been since being filled in 1937 after the construction of the Hoover Dam. The declining water levels are a result of a nearly continuous drought for the past two decades coupled with increased water demands in the Southwestern United States. (Photo by Ethan Miller/Getty Images)

BOULDER CITY, Nev. (AP) — A transformer exploded at Hoover Dam, producing a thick cloud of black smoke and flames that quickly were extinguished. Authorities say no one was hurt in Tuesday’s explosion and electricity continued to flow to the 8 million people in Arizona, Nevada and Southern California who rely on it. The U.S. Bureau of Reclamation says the fire ignited around 10 a.m. and was put out within 30 minutes. Hoover Dam is located on the Nevada-Arizona border about 25 miles southeast of Las Vegas. It’s a popular tourist destination. Some visitors captured the fire and smoke on video and quickly shared it on social media.