The fire started on June 26, 2011, at approximately 1:00 pm Mountain Daylight Time when a tree fell on a power line. On the first day, driven by strong and unpredictable winds, the fire burned 43,000 acres—a rate of about an acre per second. By the evening of the first day of the fire, no part was contained, according to local fire officials, and the county was put under voluntary evacuation. The fire burned over 61,000 acres by the end of the day on June 27, pushed north by winds into the Pajarito Mountain Ski Area. The fire also burned south, threatening the town of Cochiti, New Mexico. On June 28, this estimate was increased to nearly 61,000 acres. On June 29, it was reported that the fire was 3 percent contained, 12 miles southwest of Los Alamos, and had burned nearly. By then the fire had pushed farther north into the land owned and held sacred by Santa Clara Pueblo. By June 30, the burned area had increased to over, making it the largest fire in New Mexico history. Mandatory evacuation orders were issued for Los Alamos as of June 27, and Los Alamos National Laboratory was closed to all non-essential personnel. The evacuation order was lifted on July 3, at which time Los Alamos residents were allowed to return to their homes. The Los Alamos National Laboratory re-opened on July 6. As of July 14, 2011, the fire was 57% contained. On June 27, a one-acre spot fire burned on Los Alamos National Laboratory until firefighters extinguished it. Authorities reported that the fire did not threaten essential buildings. That was the only time the fire burned on lab property, as the fire then moved away. The fire was 100% contained on August 3 and efforts are now underway for recovery of the burned areas. Sixteen thousand acres of Santa Clara Pueblo burned in the fire, much of it in the pueblo's watershed. Forty-five percent of the watershed was burned, leading to fears of flooding. The pueblo responded by preparing for floods. Currently, much of the burned area is still at risk for dangerous flash floods. Destructive flooding occurred in the burned region as the result of a monsoon rainstorm on August 21.
