The massive Wallow wildfires raging Arizona's eastern border forests expanded to 389,000 acres by Wednesday as strong winds carry toward New Mexico, now covering an area larger than the city of Phoenix. El Paso Electric warned that 90,000 people could go without power by Friday if their lines are damaged.

Officials ordered the evacuation of around 8,000 residents from two towns of Springerville and Eagar on Wednesday, and the flames are threatening power supplies, which may lead to rolling blackouts across parts of Texas and New Mexico, ABC News reported Thursday.

The wildfire, which started by campers in the Bear Wallow Wilderness area on May 29, could engulf a pair of transmission lines that supply electricity to hundreds of thousands of people in New Mexico and Texas. The blaze ranks as Arizona's second-largest forest fire on record.

The fire destroyed 11 buildings, but no serious injuries have been reported. Authorities believe the fire was started on May 29 by an unattended camp fire. After the fire went out of control, strong winds fanned it. So far, firefighters are having trouble battling the flames.

However, fire officials spoke guardedly late Wednesday as they faced the 12th day of the fire fight. Don't get complacent just because we don't have a red flag warning. Ten to 15 mph winds are good winds to drive fire, especially through grass, so we're going to have to be very careful, fire information officer Jim Whittington told Salt Lake Tribune.

Amid ciritical fire weather conditions, the National Oceanic and Atmospheric Administration's (NOAA) national weather service has issued a red flag warning for southeastern Arizona, most of New Mexico, as well as parts of northern Texas, Colorado and Oklahoma. 

Meanwhile, El Paso Electric Co. said the Wallow Fire is heading towards a high-voltage link that deliver 40 percent of the power used by 371,000 homes and businesses in western Texas and southeastern New Mexico.

The Wallow Fire in eastern Arizona is about 15 miles from El Paso Electric’s Springerville-Luna transmission line and is expected to reach the transmission lines in the next three days, if it continues to move at its current pace.

Arizona’s largest fire is called the Rodeo-Chedeski Fire that occurred in 2002 and burned 467,000 acres. Meanwhile, the Horseshoe Two Fire burning near Portal, Arizona is about 107,000 acres and is estimated at 50 percent containment.

A blackout results in total loss of power in an area and is the most severe form of power outage that can occur. Blackouts which result from or result in power stations tripping are particularly difficult to recover quickly. Outages may last from a few minutes to a few weeks depending on the nature of the blackout and the configuration of the electrical network.