More than 304,000 people were without power Thursday evening as a massive winter storm lashes the central U.S. with heavy snow, ice and freezing cold rain, according to the national database PowerOutage.us. The weather also accounted for more than 5,000 flight cancellations and 2,400 delays on Thursday, FlightAware reports.

In parts of Tennessee, significant icefall of up to half an inch coupled with sizable sleet and snow accumulation has damaged trees and downed power lines, according to the National Weather Service and the City of Memphis. More than 100,000 residents in Memphis alone reported outages by Thursday afternoon. The state is seeing the most outages in the country, with over 146,000 residents in the dark, PowerOutage.us reported. 

The storm also means roads in the state are slick. A crash involving 16 vehicles in Memphis sent six people to the hospital, two of whom had critical injuries, according to the Memphis Fire Department. Residents are advised to avoid the Austin Peay Highway area and to “expect significant delays.”

With more heavy mixed precipitation forecast through the night, the NWS said Memphis residents can expect even more falling tree branches and power outages. City officials said Thursday that they are calling in as many outside crews as possible to help with the conditions, according to CBS affiliate WREG. 

Meanwhile, in parts of Texas where winter storm warnings, wind chill advisories and freeze warnings are in effect, outages topped 21,000 Thursday evening, according to PowerOutage.us. Certain parts of south central Texas could be in for up to half an inch of ice, according to the NWS, creating the possibility for more downed power lines. 

Peter Lake, chairman of the Public Utilities Commission of Texas, insisted Thursday that the state’s grid is “strong, reliable and is performing well in this winter weather event.”

The Austin-Travis County EMS renewed calls for people to stay off the icy roads after responding to a 14-vehicle crash on an interstate in Georgetown Thursday afternoon. It was not clear if anyone was injured. Local police tweeted that they were responding to “multiple wrecks that are blocking lanes of traffic” on the interstate.

“We are dealing with one of the most significant icing events that we’ve had in the state of Texas in at least several decades,” Texas Governor Greg Abbott said Thursday afternoon at a news briefing. 

As of Thursday evening, Ohio was reporting the second highest number of outages in the country, with 74,930, according to PowerOutage.us.

Arkansas, Kentucky, West Virginia and Pennsylvania also reported power outages.

The weather is expected to continue to impact travel beyond the thousands of cancellations and delays reported Thursday. Delta said it anticipates canceling 300 flights on Friday, while United said it has already canceled more than 430 flights.

The widespread national outages come just a year after a record winter freeze throughout Texas and much of the South left millions without power and caused at least 24 deaths.