(CNN) — A throng of rescue workers scoured the coastal Florida waters early Wednesday morning looking for two people missing from an air ambulance crash.
Authorities have already found the bodies of two others in the Atlantic Ocean, a U.S. Coast Guard spokesman said. The four passengers — two pilots, a doctor and a nurse — had just dropped off a patient at Fort Lauderdale-Hollywood International Airport and was headed back to Mexico, airport spokesman Greg Meyer said.
By early Wednesday, the debris field and search area for survivors had stretched to 20 square miles of the Atlantic, the Coast Guard said.
A distress call from one of the pilots came just moments after takeoff.
“We have an engine failure,” the pilot said.
An air traffic controller asked him to turn left and keep a certain altitude.
“Not possible,” the pilot responded. “We’re going to do a 180, and we’re going to land.”
But seconds later, he said: “Mayday, mayday, mayday.”
Coast Guard Petty Officer Mark Barney said the bodies of a man and woman were located just off the coast of Fort Lauderdale.
The two medical staff members worked for Air Evac International, said Albert Carson, the company’s director of operations. The pilots worked for a chartered company. Carson said it was not immediately clear who was killed and who was still missing.
“We’re waiting on pins and needles … waiting for more information,” Carson said late Tuesday night.
Air Evac International has several bases in Mexican cities that are popular with tourists, as well as in Costa Rica and San Diego. Carson said many of its patients are tourists, but could not comment specifically about this flight mission.
The Learjet 35 plane, which can carry up to eight passengers, was headed to Cozumel, Mexico, officials said.
The National Transportation Safety Board is investigating.
By Holly Yan and Aaron Cooper
CNN’s Dave Alsup and Janet DiGiacomo contributed to this report.