Cleanup is underway after a strong storm system spawned hail, rain, high winds and tornadoes across the southern U.S. over the weekend. At least four people were killed. A National Weather Service official says that as of Monday afternoon, over 30 tornadoes had been confirmed. Crews were working through reports of about 50 tornadoes thought to have struck over the weekend from Texas to South Carolina. The storms came over a busy holiday travel weekend, causing some treacherous road conditions along with delays or cancellations at some of the busiest U.S. airports.