Authorities say one person died after a Cessna 172 plane crashed off Elliott Key around 3:25 p.m. Sunday.
Police say there's an active search involving divers and helicopters for any other possible victims.
Miami-Dade Fire Rescue officials say they do not know how many people were on board, but the plane has four seats.
Authorities are investigating what may have caused the crash.
No further details were released.