Most of the lanes of the Tappan Zee Bridge north of New York City have reopened after a crane collapsed across the entire width of the bridge, but transportation officials are still advising motorists to plan for extra delays during the Wednesday morning commute.

A crane boom from an adjacent bridge project crashed down across the key Hudson River crossing Tuesday, forcing cars to swerve out of the way and halting traffic for hours.

Transportation officials announced Tuesday night that six of the seven lanes on the bridge had reopened ahead of schedule and that the one remaining southbound lane would remain closed until further notice.

No cars were hit when the crane collapsed and no one was significantly hurt.

“Miraculously, there were no serious injuries,” said New York Gov. Andrew Cuomo. “If you said to me that a boom could fall across the Tappan Zee Bridge at noon, not hit a car … I would not believe it.”

Cuomo said the crane was performing routine work on the new Tappan Zee Bridge, driving pilings into the river bottom, and it was unclear what caused its boom to fall across the entire 90-foot, seven-lane width of the old bridge. Officials said five people suffered minor injuries.

Nicholas D’Emealio, of Irvington, was in a vehicle about three football fields away from the crane, toward the center of the 3.1-mile-long bridge between Westchester and Rockland counties, when he heard a bang and his driver slammed on the brakes.

“It shook the whole bridge,” he said. “At first I thought the bridge was collapsing because this is not a good bridge.”

Everybody was OK but stranded. D’Emealio and his friends got out of their vehicle and threw around a football to pass the time.

Over the next several hours, the boom was removed from the span and the bridge inspected for damage. Most of the lanes were reopened by Tuesday night, avoiding a traffic nightmare.

The base and treads of the movable crane sat on the unfinished new bridge. Authorities did not immediately say how tall the crane was.

After the crash, several boats carrying emergency workers maneuvered in the river around the collapsed crane arm, while other workers appeared to be scanning the water around the wreck.

Rockland County had a helicopter and marine unit at the scene, county Executive Ed Day said. He tweeted that the crane operator was shaken but not hurt.

The new Tappan Zee Bridge has been under construction for three years and is expected to be completed by 2018 at a cost of $3.9 billion. It is being built alongside the original Tappan Zee, which dates to 1955.

In March, a 90-foot-long tugboat hit a construction barge near the bridge site and sank, killing three crew members.

In 2013, a powerboat plowed into a construction barge at the bridge, killing a bride-to-be and her fiance’s best man. The boat’s driver, who had nearly twice the legal limit of alcohol in his system, pleaded guilty to vehicular manslaughter and was sentenced to two years behind bars. The victims’ families, however, attributed the crash mainly to bad lighting on the barge.

(AP)