Traffic sits at a standstill Tuesday along westbound I-20 near Cedar Ridge Drive and Loop 408 in Dallas. Several vehicles, including semi-trucks, were unable to make it up a hill causing traffic to stop. (Elías Valverde II/The Dallas Morning News via AP)

AUSTIN, Texas (AP) — Bands of sleet and snow that brought traffic to a standstill across the nation’s midsection, canceled thousands of flights and were blamed for six deaths caused dangerous conditions for a third day today in several Southern states.

Watches and warnings stretched from Texas to West Virginia. Several rounds of mixed precipitation, including freezing rain and sleet, were in store for many areas throughout the day, meaning some regions could be hit multiple times, forecasters said.

More than 1,400 flights scheduled for today nationwide had already been canceled by this morning, according to the tracking service FlightAware. The list for cancelations included both major airports in Dallas and airports in Austin, Texas, and Nashville, Tennessee.

As the ice and sleet enveloped Memphis, Tennessee, Memphis-Shelby County Schools announced it would cancel classes this morning due to freezing rain and hazardous road conditions. The school system has about 100,000 students. The National Civil Rights Museum in Memphis was also closed due to the weather.

The Dallas Independent School District, with about 145,000 students, also canceled classes this morning.

Emergency responders rushed to hundreds of auto collisions across Texas on Tuesday and Republican Gov. Greg Abbott urged people not to drive. At least six people died on slick Texas roads since Monday, including a triple fatality crash Tuesday near Brownfield, about 40 miles southwest of Lubbock, and two law officers in the state were seriously injured, authorities said.

In Arkansas, Republican Gov. Sarah Huckabee Sanders declared a state of emergency Tuesday because of icy conditions. Her declaration cited the “likelihood of numerous downed power lines” and said road conditions have created a backlog of deliveries by commercial drivers.