At least two bodies have been recovered Sunday at the site where a twin-engine cargo plane carrying three people crashed into a bay east of Houston, according Chambers County Sheriff Brian Hawthorne. The Boeing 767-300 plane, operated by Atlas Air Inc., originated from Miami International Airport and lost radio contact approximately 30 miles southeast of Houston's George Bush Intercontinental Airport. Officials said surveillance video shows the plane for five seconds "in a steep descent with its nose down."

CBS News learned moments after a Sunday press briefing that Mesa Airlines confirmed one of its employees was onboard Atlas Air Flight 3581 on Saturday, identified as Captain Sean Archuleta, who had been a pilot for Mesa since 2013 and had been riding in the aircraft's jump seat.

"This is a sad day for the entire Mesa Family as we mourn the loss of Captain Sean Archuleta," said Jonathan Ornstein, the company's chairman and chief executive officer. "Our thoughts are with Sean's family, the families of the two Atlas Air pilots, and the whole Atlas Air organization. This is a loss for all of aviation."

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The identity of the other two victims was not made immediately clear.

CBS News

The National Transportation Safety Board (NTSB) said in Sunday's briefing that finding the plane's black boxes are a "high priority" as investigators search through the debris field. NTSB chairman Robert Sumwalt said they are having trouble locating the black boxes because they are apparently submerged too far in the muddy bay for their location to be tracked using their "pingers." He explained scuba divers, teams wading in the water or dredging will be used if needed.

NTSB said video footage of the plane prior to the crash — captured by a camera from a jail about a mile away — won't be made public for quite some time as the investigation continues.

Video from CBS affiliate KHOU-TV showed wreckage in the shallow water of Trinity Bay. There was rain in the area when air traffic control lost contact with the plane.

The cargo plane had been carrying packages for Amazon's Prime Air service. It was on approach to Houston's airport when air traffic controllers warned the pilots they were approaching bad weather.

Saturday, Boeing tweeted a statement saying it was aware of the crash and "gathering more information."

Jason Campbell was one of the civilian boaters at the site of the crash Saturday and described the grim scene.

"Pieces of bodies, nothing bigger than ... you know," Campbell told KHOU-TV. "It's obvious it's human pieces, but nothing bigger than you can hold in your hands."

The field of debris after a Boeing 767 cargo plane crashed east of Houston on Sat., Feb. 23, 2019. CBS News

Justin Carissimo and Kris Van Cleave contributed to this report.