For the first time in recorded history, downtown San Francisco was included in a tornado warning on Saturday as severe storms swept through the city, just one week after a tsunami warning triggered widespread panic in the region.

A major ice storm has created treacherous driving conditions across Iowa and eastern Nebraska and prompted temporary closures of Interstate 80 after numerous cars and trucks slid off the road.

San Francisco residents were woken up by a tornado warning early Saturday morning during a powerful storm system that battered the region with heavy rain and wind.