Authorities said that at least two people are dead and at least 68 others were injured in a 100-car pileup on a bridge in South Korea near the Incheon International Airport.

The Korea Herald reported that the accident occurred Wednesday, just after 9:30 a.m. local time on the Seoul-bound lanes of the Yeongjong Bridge, which connects Incheon’s Yeongjong Island to the mainland.

Of the injured at seven are said to be serious.

The Associated Press noted that Park Sang-yeoul, an official from the Incheon Seobu Police Station, estimated that around 100 cars were involved in the vehicle pileup.

Officials believe that fog may have played a role as some survivors of the crash said they had limited visibility due to the dense fog and could barely see in front of them. However, law enforcement is still trying to determine the exact cause of the accident.

“We are looking into nearby CCTV footage to determine the exact cause of the accident,” a police officer said.

Incheon International Airport is the largest in South Korea and primarily serves the Seoul area.