No cars were hit by the crane’s arm as it came down around noon, but Rockland County Executive Ed Day wrote on Twitter that three people suffered minor injuries when vehicles swerved and stopped to avoid the wreckage.

Video from a news helicopter showed at least one person being removed from a car and loaded into an ambulance.

Nicholas D’Emealio, 21, of Irvington, New York, was in a vehicle about three football fields away from the crane, toward the center of the bridge, 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 they were stranded. He and his friends got out of their vehicle and threw around a football to pass the time.

The base and treads of the huge, movable crane sat on the unfinished new bridge, which crosses the Hudson River between Westchester and Rockland counties. Part of the toppled crane lay across the old bridge, which runs parallel to the new one. Another section lay across a construction platform in the water between the two spans.

Officials didn’t immediately give the length of the collapsed crane. But according to TV pictures, the crane was anchored on the roadway of the new bridge, and broken pieces of its arm covered the distance between the new and old spans, as well as the entire 90-foot, seven-lane width of the existing bridge.

Several boats carrying emergency workers were maneuvering 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, according to Day. The county executive 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 span, which dates to 1955.

In March, a 90-foot tugboat sank after it hit a construction barge near the bridge site, 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.