The first crash happened at about 9:30 a.m. in the northbound -- or Rockland County-bound --lanes of Interstate-87 on the bridge.
State police said crash-after-crash happened after the first one, resulting in at least six separate crashes involving about 25 vehicles.
Four injuries were reported, including a woman who was thrown from her car and pinned against the guardrail. All suffered non-life threatening injuries.
State police temporarily shut down the southbound side -- or Westchester County-bound -- lanes to allow ambulances to get to the scene.
As of 2:45 p.m., all but one Westchester-bound lane have reopened to traffic. Though, residual delays are likely throughout the afternoon.
Eyewitness News Reporter Marcus Solis was live on the bridge. Watch his report here:
The bridge continues to be extremely slippery because of the winter weather conditions.
All drivers on the bridge were stuck in stand-still traffic.
* More Northern Suburbs news
* Send us a news tip
* Download the abc7NY app for breaking news alerts