Shelters were opened across northwestern Connecticut Sunday, as tens of thousands of people remained without electricity due to a weekend ice storm that snapped trees and brought down power lines.

State and local officials were preparing for a second round of frozen rain Sunday night. Weather forecasters said the storm was expected to end Monday morning.

At the height of outages Sunday, more than 130,000 Connecticut Light & Power customers were without power. There were 80,326 outages reported at 10 p.m.

“Just to get to some of the trouble spots, we need tree crews to go ahead of our line crews,” said Frank Poirot, a spokesman for CL&P. “It makes for a very labor-intensive, long restoration effort.”

Poirot said the company expected to restore power to 99 percent of customers who lost electricity by early Wednesday morning.

CL&P had nearly 300 of its workers trying to restore power. The company also brought in 214 people from private contractors to remove trees and another 200 utility workers from Western Massachusetts, Boston and New Hampshire.

The hardest hit areas were northwest of Interstate 84, where about a half inch of ice accumulated by dawn Sunday, state police said. No major injuries were reported in northwest Connecticut, but authorities were trying to determine whether a fatal accident in Colchester in the eastern part of the state Saturday night was related to the storm.

Residents in the northwest hills said it was the worst ice storm to hit the area in a long time. Many people reported hearing loud cracking sounds as the ice overcame trees.

–Associated Press