Schools and government offices were closed again on Thursday as the mid-Atlantic and Northeast dug out from deep snowfall left behind by Winter Storm Toby, which was responsible for at least three deaths.

Authorities in Toms River, New Jersey, confirmed the death of an 87-year-old woman who was found dead in the snow early Thursday morning about a mile from her house, according to NBC New York. Police said she suffered from Alzheimer's and dementia, the report added.

New York Police reported one person died and five others were injured on Long Island when a van flipped over amid wintry conditions on the Wantagh State Parkway in Nassau County, according to the AP. The victim, who was not identified, died in the crash that occurred at about 10 a.m. EDT Wednesday morning, the report added.

In Bellmore, New York, a 62-year-old woman died of a heart attack while shoveling snow late Wednesday night, Nassau County officials told the AP.

New Jersey Gov. Phil Murphy said Thursday that a person he reported dead in a car crash along Interstate 78 Wednesday in Hunterdon County is actually alive but in intensive care, the Associated Press reported. He did not give additional information, the report added.

(MORE: When the Next Winter Storm Could Arrive)

The storm's biggest snow totals were on Long Island, where more than a foot and a half of wintry precipitation accumulated by Thursday morning. Officials asked residents to avoid travel until plows could get out and clear the snow.

"Our roads are treacherous, and if you can stay off the roads, please do," Nassau County Executive Laura Curran told reporters. "Earlier this morning, we were reminded of how important this is. Due to inclement weather, there was a fatal accident on the Wantagh Parkway."

The storm brought down numerous trees and power lines in Atlantic County, New Jersey, according to the National Weather Service. It could be several days before power is restored to all customers affected by the outages, the report added.

Some schools remained closed Thursday in Pennsylvania, Boston, downstate New York and New Jersey. More than 100,000 homes and businesses were without power in the mid-Atlantic and Northeast as of Thursday morning, according to Poweroutage.us.

Many residents expressed their ire toward yet another snowstorm, especially because this one came on the second day of spring.

"We're supposed to be getting ready for Easter, not a nor'easter," Raeme Dempsey told the AP in Philadelphia.

(MORE: What 4 Consecutive Nor'easters Looked Like from Space)

Upwards of 4,000 domestic flights were canceled Wednesday, most of which were because of Toby, according to the flight-tracking website FlightAware. Airports will attempt to catch up, but at least 500 additional flights were canceled at the major Northeast airports.

State offices were closed Wednesday in Rhode Island and New Jersey, and states of emergency were declared in Delaware, New Jersey and downstate New York.

As travel conditions worsened Wednesday morning, Virginia State Police troopers responded to more than 250 crashes statewide during the morning rush hour. In Richmond, state offices opened two hours late Wednesday morning, Gov. Ralph Northam said.

(MORE: What Happens If Schools in the Northeast Run Out of Snow Days?)

Pennsylvania Gov. Tom Wolf put more than 450 National Guard members on standby in case they were needed for storm response.

In New York City, Justin Timberlake announced his Wednesday night concert at Madison Square Garden was canceled because of the winter storm.

Two Philadelphia police officers were taken to the hospital Wednesday after their vehicle spun out on Interstate 95 and struck a guardrail, 6ABC.com reported. Their conditions were not immediately available, but both were conscious as they were transported.