The seventh lane is set to remain closed for repairs until further notice.
The crane was one of 28 being used to build the new Tappan Zee Bridge. New York Governor Andrew Cuomo said it was not immediately known yet what caused the crane to malfunction and collapse.
Cuomo said the three northbound lanes from Westchester to Rockland County have been reopened. The southbound lanes will reopen Tuesday evening.
"We have to place plates on the roadway to make those roadways safe. There was some surface damage. Putting the plates on, moving the barriers, will take some time," said Cuomo.
Eyewitnesses said the crane started falling slowly, and then literally crashed down onto the highway.
"Luckily, there were no cars right under it," Balam Arana said. "There were no cars getting hit, or anything like that. There was an accident, though, right in front of me and literally in front of the crane.
Listen to the full eyewitness account from Balam Arana:
Officials said two women and a man suffered minor injuries in that accident.
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.
One Tappan Zee Bridge worker also suffered minor injuries, authorities said. THe crane operator was also being checked out, but seems to be fine.
"If you said to me that a crane could fall across the bridge with the boom at noon and not hit a car or a person, I wouldn't believe it. So I'll say a special prayer tonight," Cuomo said.
The process of getting vehicles off the bridge was underway by 1:00 p.m., but hundreds remained stuck on the highway for hours.
After the crane and debris are removed, crews must determine the structural integrity of the bridge.
Cuomo said that one southbound lane did appear to have sustained significant surface and structural damage.
Six out of seven lanes on the Tappan Zee Bridge have been reopened to traffic ahead of schedule.
Three lanes will be open in each direction until further notice. Motorists traveling over the Tappan Zee Bridge should plan for extended delays during their morning and evening commutes.
The detours at exits 15 and 12 are no longer in effect.
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.
Some information from The Associated Press
Photos from the scene shared via social media:
Exclusive view from the Hudson of the crane collapse at the Tappan Zee Bridge. pic.twitter.com/AwM51dzM5w— Marcus Solis (@MarcusSolis7) July 19, 2016