The search goes on for a Queens man after a small plane went down in the waters off Long Island over the weekend.

Gerson Salmon-Negron, 23, is still missing after the Piper PA-28 went down in Port Jefferson Harbor around 11 p.m. Saturday.

Three other people who were on the plane were rescued.

Authorities say engine trouble forced the instructor pilot to take the plane into the water.

"If it weren't for the bold actions of the Suffolk County police officers standing behind me and the fire department and the firefighters standing behind me, we don't think the three individuals would have survived," said Suffolk County Police Commissioner Tim Sini. 

The group was headed from Massachusetts to Republic Airport in Farmingdale.

The Federal Aviation Administration and the National Transportation Safety Board are both investigating.