A pair of wrong-way accidents left three people dead and several others injured during a deadly five-hour span in Essex and Union counties, authorities said.

Gustavo Cunha, 23, of Elizabeth and Pingai Liwu of San Francisco died after a Toyota 4Runner slammed into a Mazda on Routes 1 & 9 South in Newark around 10 p.m. Monday, said Katherine Carter, a spokeswoman for the Essex County Prosecutor's Office.

Cunha was a passenger in the Mazda. Liwu, whose age was not available, was a passenger in the Toyota, Carter said.

The Toyota was traveling north in the southbound lanes at the time of the crash. Cunha was pronounced dead at the scene, according to Carter, and Liwu died several hours later at University Hospital. Three other passengers in the vehicles were treated for non-life-threatening injuries.

Alcohol did not appear to play a role in the crash, according to Carter, who said authorities are still trying to determine why the Toyota was traveling the wrong way. The case will be presented to a grand jury, said Carter, and criminal charges have not been filed.

Hours later, Luis Padilla, 32, was driving the wrong way on Route 78 West outside of Springfield when his Volkswagen collided with a tractor-trailer, said acting Capt. Frank Davis, a State Police spokesman.

A passenger in Padilla's vehicle died at Overlook Hospital in Summit a short time after the crash. Authorities believe he is an immigrant from another country, but a State Police spokesman said his identity could not be immediately confirmed.

Authorities said they are still trying to determine the cause of the crash.