Jimmy Emilio, general manager of Chuuk Airport at Weno in Micronesia, told news agency Reuters by phone, "It was supposed to land but instead of landing it was 150 yards short and she went down".
Social media posts shows a series of small boats helping passengers from the submerged aircraft.
The aircraft, a Boeing 737-800, flew into a lagoon near Chuuk International Airport on Weno island. The flight is part of the airline's bi-weekly service between the Federated States Of Micronesia and Port Moresby.
Emilio has since confirmed that all of the 36 passengers and crew members on board the plane are accounted for and safe, reported PDN.
Only the top half of the plane was visible in a photo obtained by RNZ Pacific, and small boats boarded with people were scattered around it. "So far, we don't know why they went down".
Passenger Bill Jaynes, editor of the Pohnpei-based Kaselehlie Press newspaper said he did not even realise there had been an accident until he saw water gushing into the fuselage.
Passenger Plane Misses Runway, Crash-Lands in Ocean
The typical passengers would be business people from Micronesia, Papua New Guinea and Australia, Harris said, as well as some tourists.
The Air Niuguini plane crashed on approach to Chuuk Airport in the Federated States of Micronesia.
The plane was being operated by Air Niugini, the national airline of Papua New Guinea.
The airline said the plane, which was involved in a collision with another aircraft earlier this year, had "landed short of the runway".
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Constand's was the only case that was within the statute of limitations, and is so far the only criminal case filed against him. Ms Constand, now 45, said she has suffered with anxiety and self-doubt for years in a statement submitted to the court.