A person walks past parked snow-covered cars Monday, Feb. 15, 2016, in Philadelphia. Photo: Clem Murray/The Philadelphia Inquirer via AP

A person walks past parked snow-covered cars Monday, February 15, 2016, in Philadelphia. Photo: Clem Murray/The Philadelphia Inquirer via AP
A treacherous mix of falling snow, sleet and freezing rain turned Tuesday commutes to misery for many returning from a long holiday weekend in the US Northeast. In Washington, the federal government was opening three hours late after freezing rain coated the nation's capital and surrounding areas in ice. Meanwhile, officials in Florida and Mississippi were investigating reports of at least three possible tornadoes.