A United Airlines flight dove 1,400 feet toward the Pacific Ocean shortly after taking off from a Hawaii airport in December, according to flight-tracking data, in an incident that prompted a federal investigation.

The Boeing 777 came within 800 feet of the water near the Maui airport, tracking site Flightradar24 reported, before reversing course and climbing, then continuing to San Francisco without additional problems.

No one was injured, and the cause of the rapid descent is not clear. The Dec. 18 incident was first reported by aviation news site Air Current.

United said in a statement that the pilots filed a safety report when they arrived in San Francisco and that the airline worked with the Federal Aviation Administration and the pilots’ union to investigate. The pilots, who have 25,000 hours of flight time between them, received additional training at the conclusion of the investigation, United said.

“Safety remains our highest priority,” the airline said.

The FAA said the pilots reported the incident through a voluntary safety information sharing system. The agency said the reports are typically kept confidential to encourage reporting.

The incident adds to a number of near disasters in recent months.

In January, an American Airlines jet was crossing a runway at New York’s John F. Kennedy International Airport as a Delta Air Lines plane was about to take off. Earlier this month, a FedEx cargo plane came within about 100 feet of a Southwest Airlines jet at Austin-Bergstrom International Airport when they were both cleared to use the same runway.

The National Transportation Safety Board is investigating both of those incidents.