The Throgs Neck Bridge was closed Friday morning - and is expected to be closed for hours - as firefighters fought a blaze on a construction platform under the bridge connecting Queens to the Bronx, officials said.

The incident has morning rush-hour traffic backed up for miles with delays on the Cross Island Parkway causing snarls as far back as the Long Island Expressway.

The fire broke out under the Queens side of the bridge sometime around 5 a.m., FDNY officials said. Officials first closed some lanes, but the New York State Department of Transportation said the entire bridge was closed by 6:30 a.m.

The bridge was expected to be closed at least four hours, according to the NYSDOT.

It is unclear if the fire has caused any structural damage to the bridge or if it will need repairs before it can be reopened to traffic.

The NYSDOT is recommending motorists plan on using alternate crossings Friday.

However, a scan of traffic maps shows that traffic is already at a crawl on the nearby Whitestone Bridge Friday.