CARTERET - Authorities have reopened the New Jersey Turnpike truck lanes after uprighting two tanker cars following an earlier train derailment in Carteret.

The lanes were shut down for hours while emergency crews worked to upright the cars, which were carrying a flammable liquid, after they derailed near Roosevelt Avenue. According to fire officials, the two cars were carrying two different types of acetates when they went off the tracks at around 1 a.m.

Interchange 12 on the Turnpike had been shut down as a precaution. Authorities also closed the northbound truck lanes between the South Brunswick split and exit 13.

Officials have listed human error as a preliminary cause. They say a piece of equipment known as a "derail unit" was left on the tracks. The train conductor struck the unit this morning, not realizing it was on the tracks.

The tankers were not compromised and did not leak, fire officials said.

Nearby buildings, including a Holiday Inn, were evacuated but have since been reopened.