COLUMBIA, S.C. — Snow spread across much of South Carolina on Monday, causing hundreds of car accidents and closing schools, state offices and the Greenville-Spartanburg International Airport. Gov. Mark Sanford declared a state of emergency.

Six inches of snow had fallen in the Greenville-Spartanburg area by late Monday morning, and forecasters said the total could reach 12 inches by early Tuesday. Six to 9 inches of snow were possible around Rock Hill. Authorities urged people to stay home.

A blanket of snow coated Columbia, where government offices closed and students returning from a holiday break to the University of South Carolina got an additional day off. In all, 2 to 5 inches were forecast to fall before turning to freezing rain in the central part of the state.

In northeast Columbia, 15-year-old Connor Ormond trotted to a friend's house, snowball in hand.

"I'm trying to have a snowball fight with my friend," Ormond said. "This is the most snow I've ever seen!"

Two or 3 inches of snow was forecast for the Florence area and snow was expected to reach Myrtle Beach later in the day. Less than an inch of snow was expected farther south, around Moncks Corner and Summerville.

But rain and temperatures near freezing led officials to temporarily close most bridges around Charleston, including the Ravenel Bridge linking downtown with Mount Pleasant. Local television outlets were reporting minor accidents on the 3-mile-long span, which has steep approaches.

The bridge was reopened as midday temperatures climbed above freezing.

The National Weather Service said the snow and freezing rain were expected to continue through Tuesday morning and temperatures were predicted to stay at or near freezing until Tuesday afternoon.

Sanford closed state offices and many local government officials followed his lead. Gov.-elect Nikki Haley canceled plans to announce a Cabinet appointment ahead of her scheduled inauguration on Wednesday.

The Emergency Management Division's emergency operations center was monitoring conditions, spokesman Derrec Becker said. The Highway Patrol was getting help from the State Law Enforcement Division and Natural Resources Department, Becker said.

More than 400 accidents had been reported around the state and several roads and interstate ramps were closed intermittently during the day until work crews could clear them or spread sand and salt for better traction.

"We are expecting conditions to get worse," said Highway Patrol Sgt. Kelley Hughes. "People need to go home and stay."

Becker said the National Guard was standing by if needed, and the armory in Allendale County was opened as a shelter for those who needed a warm place to stay.

Fewer than 5,000 power outages were reported Monday, though the state's utilities were prepared for more as temperatures were forecast to drop into the low 20s overnight.

House Speaker Bobby Harrell delayed Tuesday's regular noon start for the Legislature until 3:30 p.m. because of worries about travel. The Senate planned to meet at noon as scheduled.

More than 1,300 Transportation Department employees were working on the roads Monday, spokesman Pete Poore said.

The Dorn VA Medical Center said its outpatient clinics in Columbia, Spartanburg, Greenville, Anderson, Rock Hill, Florence, Sumter and Orangeburg were closed Monday.

Associated Press Writer Seanna Adcox contributed to this report.