A massive Arctic air mass settled over the central United States on Monday, spawning deadly accidents, leaving millions without power and breaking records for snowfall and low temperatures from Nebraska to Oklahoma to Texas. In Houston, 1.4 million people remained without electricity for a second straight day after the city recorded an all-time record low of just 17 degrees. This is Houston Mayor Sylvester Turner.

Mayor Sylvester Turner: “It is a system-wide failure across the state. … These are not rolling blackouts. These are power outages at a huge, unprecedented scale.” 

Climate scientists say severe winter weather has become much more frequent as the Arctic warms rapidly due to human activity.