A man’s missing after a watercraft he was working from capsized in the Mississippi River.

Conservation officers say the man, whose name has not been released, is from Florida and in his 20s. He was part of a construction crew working on a bridge spanning the river. He was out alone on a “plate boat,” a vessel designed as a work platform on water. When that boat capsized, a little before nine a.m., it was windy which may have been a factor in the mishap.

The man disappeared underwater and searchers so far haven’t been able to find him.