A small plane crashed on Interstate 684 in Westchester County at around 7 p.m. Thursday, killing one of its two occupants, New York State Police said.

The crash occurred on I-684 near Exit 2 in the town of Harrison, closing the interstate in both directions and requiring detours, police said.

The crash also caused an aviation gas spill, which members of the state Department of Environmental Conservation were working to contain and clean up, Gov. Kathy Hochul said.  

Motorists were asked to avoid the area, as the closure time was expected to be significant, according to authorities. 

A preliminary investigation determined there were two people on the plane. One was confirmed deceased, police said. The other individual in the plane was in serious condition, Hochul said.