Just a few hours after Interstate 90 had been reopened, a second avalanche containing snow and debris such as three, rocks and anything else it carried along tumbled on the highway Wednesday afternoon.

The pass will remain closed for the day at the very least, said the state Department of Transportation (WSDOT). This time the cleaning process will take longer and will be more difficult because of the debris carried by the slide. Last time, the cleaning process took 28 hours as units specialized in clearing roads managed to remove the equivalent of 200,000 dump-truck loads of snow from two lanes.

The second avalanche occurred at approximately 2:45 p.m. Wednesday. Two vehicles remained stuck in the slide somewhere near the west end of the Denny Creek Bridge, about a mile and a half west of the Snoqualmie Pass summit, said WSDOT spokesman Mike Westbay.

Fortunately, no one was hurt and the cars weren’t severely damaged, but authorities were forced to close the roadway on Wednesday night eastbound at Edgewick, milepost 34, and westbound near Ellensburg, milepost 106.

Meteorologists forecasted that an additional 12 to 16 inches of new snow will fall overnight and an additional 3 feet are expected by the end of Friday.

Approximately $700,000 per hour is the economic loss of the closed highway, transportation officials approximated. About 6,500 to 7,000 trucks travel I-90 over the pass each day.

"We really want to get the highways open and our economy moving," WSDOT secretary Paula Hammond said. "Mother Nature has hit us hard. Our crews are out there fighting, but the snow just keeps coming."

At least 200 trucks were lined up one after another on Tuesday at North Bend on the west side of the pass.

Interstate 90 or I-90 is the longest interstate highway in the country at nearly 3,100 miles (5,000 kilometers). It is the northernmost east-to-west, coast-to-coast interstate. Its western terminus is in Seattle, Washington, at 4th Avenue S. next to Qwest Field, and its eastern terminus is in Boston, Massachusetts, at Route 1A near Logan International Airport. It crosses the Continental Divide just east of Butte, Montana.