Hoover Dam transformer explodes without interruption to power grid

A view of a fire at Hoover Dam on the border between Nevada and Arizona, U.S., July 19, 2022, in this still image obtained from a social media video. William Herro/via REUTERS

A transformer caught fire at Nevada’s Hoover Dam on Tuesday and was quickly extinguished by the fire brigade without any injuries or interruption to the power grid, the U.S. Bureau of Reclamation said.

Video circulating on social media, apparently taken by a tourist, showed a small explosion and smoke and fire coming from the base of the dam, the largest in the United States and the source for a 2,080-megawatt hydroelectric plant, enough for about 1.3 million households.

The cause of the fire was under investigation, the bureau said.

The fire at the dam’s A5 transformer started around 10 a.m. local time (1700 GMT) and was put out by the Reclamation/Hoover fire brigade within half an hour, the bureau said.

“There are no injuries to visitors or employees. There is no risk to the power grid and power is still being generated from the powerhouse,” the statement said.

Firefighters pour water on electrical transformer equipment at the Hoover Dam near Boulder City, Nevada, U.S. July 19, 2022 in a still image from video. Bureau of Reclamation/Handout via REUTERS

The Boulder City Fire Department responded but the fire was out by the time firefighters arrived, the Nevada city said.

The dam, completed in 1936, sits on the Colorado River at the Nevada-Arizona border and impounds Lake Mead, the largest reservoir in the United States. It is crucial to the water supply of 25 million people including in the cities of Los Angeles, San Diego, Phoenix, Tucson, and Las Vegas.

Water levels in Lake Mead, the reservoir created by the dam, are at historically low levels due to exceptional drought in much of the surrounding area, which was also experiencing extreme heat on Tuesday.

Boulder City, about 8 miles (13 km) from the dam, recorded a temperature of 101 degrees Fahrenheit (39 Celsius) as midday approached with a real feel of 110 F (43 C), according to AccuWeather.com.