There were two people inside of the Union City Department of Public Works truck when it crashed through a guardrail and landed onto the westbound lanes of Route 495 in Union City, New Jersey, the main conduit out of the Lincoln Tunnel, authorities said.
Occupants of three vehicles on local streets and at least five people on a bus behind the crash were also checked out for various injuries. At least three of the victims were in critical condition, but the nature of their injuries weren't immediately clear.
The accident shut down outbound traffic from the tunnel -- a move that was severely impacting July Fourth travel.
The Port Authority Bus Terminal was also temporarily shut down because buses could not get out of the city.
Bus lines resumed running later on Wednesday, but traffic remained heavy as commuters tried to leave before the July 4 holiday.
The tunnel was reopened to traffic at about 7 p.m. on Wednesday.
"The Lincoln Tunnel to NJ has reopened to all traffic," the Port Authority tweeted. "The crash on NJ-495 has cleared. There are residual delays."
Commuters had been strongly encouraged to use the Holland Tunnel as an alternate route, causing delays there as well.
The Port Authority tweeted just after 6 p.m., that "the previous alert at the Holland Tunnel to NJ due to the general volume of traffic is no longer in effect. There may be residual delays."