A fast-moving wildfire burning through the Texas Panhandle has grown into the second-largest blaze in state history. The fire is forcing evacuations and triggering power outages as firefighters struggle to contain the widening flames. The blazes tore through sparsely populated counties on the vast, high plains that are punctuated by cattle ranches and oil rigs. The main fire, known as the Smoke House Creek Fire, had grown to more than half the size of the state of Rhode Island and is five times the size it was on Monday when it began. As the evacuation orders mounted Tuesday, county and city officials implored residents to turn on emergency alert services on their cellphones and be ready to evacuate immediately. According to local emergency officials an unknown number of homes and other structures in the county were damaged or destroyed. The Pantex plant, northeast of Amarillo, evacuated nonessential staff Tuesday night out of an “abundance of caution,” said Laef Pendergraft, a spokesperson for National Nuclear Security Administration’s Production Office at Pantex. Firefighters remained in case of an emergency. The plant, long the main U.S. site for both assembling and disassembling atomic bombs, completed its last new bomb in 1991 and has dismantled thousands since. Pantex tweeted early Wednesday that the facility “is open for normal day shift operations” and that all personnel were to report for duty according to their assigned schedule. The largest of the fires has grown to nearly 800 square miles. Authorities said it jumped into parts of neighboring Oklahoma and remained completely uncontained as dawn broke Wednesday.