(CNN) -- The mayor of Danbury, Connecticut, appears to be the first to give the Northeast's ice storm a hashtag: #Icezilla.
Mark Boughton tweeted updates to his constituents about the icy weather; some of them were enduring interruptions on the metro this weekend as freezing rain coated Connecticut and Pennsylvania and pelted New Jersey and New York.
"Still slippery, but calls are slowing down in our 911 center. #Danbury #Icezilla," Boughton tweeted.
Don't drive. Just don't do it, fire and police officials are urging.
They said every surface is slick: Bridges, overpasses, interstates.
A photo on the Danbury Fire Police Facebook page shows a lighted road sign that says, "The roads are wicked slippery!"
Pennsylvania Department of Transportation spokesman Charles Metzger said conditions will warm as the day goes on, but it will continue to rain throughout the day.
Two people have died in accidents related to black ice in the Philadelphia area, state police said.
After crashing into at least 20 cars piled up on Interstate 76, one person was killed after getting out of a car and being hit by an oncoming vehicle, authorities said. Black ice coated Interstate 95 near the city, law enforcement told CNN, and there was an accident at every mile marker.
Pile-ups shut down parts of both interstates, a dispatcher said.
At least one person has died in Hartford County, Maryland, said State Police spokesman Greg Shipley.
There have been dozens of crashes throughout central and northern Maryland on Sunday, he said. Most of them occurred in Howard, Baltimore, Harford and Cecil counties.
Troopers who had worked through the night kept working when their shifts were over, and more troopers were called in to help assist passengers who had accidents, he said.
Statewide, Shipley estimates that at least 100 car accidents have occurred.
"The State Highway Administration is out in force salting" bridges, ramps and overpasses, he said.
The slick roads are causing the highest number of traffic accidents this winter in New Jersey, said State Police Sgt. Jeff Flynn.
There have been 428 accidents and 186 calls to help people who have been in accidents in areas that the police are patrolling, he said Sunday morning.
There could be other accidents the department isn't aware of yet. "So this isn't even the whole picture," Flynn told CNN.
Even a salt truck slid and crashed into three cars East Orange, New Jersey, according to CNN affiliate News12.
Flynn knows that no matter how much officials urge people to stay off the roads, many will choose to drive or feel they have to drive.
"If you have to be out," Flynn said, "drive slower than you would in the snow."
The cold is also wracking other states this weekend. Winter storm warnings are in effect through Monday morning for upstate Vermont and portions of New Hampshire, Maine and western Massachusetts.
In Vermont, there could be between 3 and 7 inches of snow and 10 inches in the state's highest elevations.