A Boeing 737 on Friday made an emergency landing off the coast of Honolulu after the pilots reported engine troubles shortly after taking off.

Both pilots were rescued by the U.S. Coast Guard, the Federal Aviation Administration said. The aircraft was traveling from Honolulu to Maui.

One of the pilots was reportedly seen being taken away in a wheelchair and conscious. Another pilot was airlifted to a hospital and taken to intensive care and is in critical condition.

The aircraft was not a 737 Max and officials say the plane had been grounded for almost two years after two fatal crashes.

The FAA said Flight 810 made an emergency landing around 2:30 a.m. local time. The FAA and the National Transportation Safety Board said they will investigate the crash.

They were forced to land the aircraft in the water, according to one FAA official. According to LiveATC recordings reviewed by CNN, the pilots told air traffic controllers that one of their engines failed moments before the flight went down.

The plane was built in 1975, according to Flightradar24.

“We are aware of the reports out of Honolulu, Hawaii and are closely monitoring the situation,” Boeing said in a statement. “We are in contact with the U.S. National Transportation Safety Board and are working to gather more information."