(CNN) -- Police expanded their search Friday for a man who either jumped or fell from a small plane as it flew off the Florida coast near Miami.
The pilot of the single-engine Piper PA-46 aircraft called air traffic controllers Thursday afternoon to say his passenger -- the only other person on board the flight -- had fallen out of the plane.
"He opened the back door and he just fall down the plane," the pilot said, according to a recording of the conversation.
The pilot said he was flying at 1,800 feet about two miles from the shore when the man fell. Authorities identified the man as Gerardo Nales, a 42-year-old man from Key Biscayne, Florida.
After searching until dark Thursday, authorities resumed their efforts early Friday, expanding the search area based on currents and weather conditions, police said.
Police think it's unlikely Nales could have survived the fall. They're describing the search as a recovery mission.
A police spokeswoman said it was unclear whether Nales accidentally fell out of the plane or deliberately jumped.
Investigators questioned the 47-year-old pilot but did not release his name. Homicide detectives also are involved, as they are in all death investigations, Miami-Dade police spokeswoman Sgt. Robin Pinkard said.
The pilot first told air traffic controllers that a door was open on the plane, then added that a passenger had fallen out.
"I have a door ajar," he said, "and a passenger that fell down."
The Piper PA-46 -- a private plane -- went on to land safely at Kendall-Tamiami Executive Airport, the Federal Aviation Administration said. Baez declined to say whether the owner of the plane was on the flight.
CNN's Catherine E. Shoichet, Alina Machado, Mike M. Ahlers and Brian Rokus contributed to this report.