BARNEGAT — A six-foot wave that crashed through Barnegat Inlet and swept three people off a jetty and into the water earlier this month is being investigated as a possible tsunami by federal officials, according to the National Oceanic and Atmospheric Administration.

The June 13 wave was observed at over 30 tide gauges and a buoy throughout the northwestern Atlantic Ocean, according to a report on NOAA's website.

The cause of the incident is "complex and still under review," the report said, but it is believed to have been connected to a strong weather system known as a "derecho," which had passed through the area shortly before the wave was reported.

The agency is also investigating whether it may have been connected to a "slumping," or collapse, of a portion of the continental shelf off the coast, the report said.

According to an eyewitness cited in the report, the incident happened very quickly.

Brian Coen told NOAA he was in a boat about 3:30 p.m. when an outgoing tide began to increase rapidly in speed. The current carried divers who had been spearfishing over a submerged band of rocks that had about four feet of water over them, he said.

In an interview with NBC News Philadelphia, Coen said the divers drifted about 100 yards in 30 seconds.

The "outrush" of water continued for one or two minutes, exposing the rocks and pulling the eyewitness’s boat out of the inlet, according to the report.

Then, Coen told NOAA, a large wave, about six feet high, as broad as the inlet itself and cresting near the top, came in along with a surge of water.

"I said, 'Wow, that wave is not backing off,'" Coen told the television station.

The water carried the divers back into the inlet, the report said, and swept three people off of a rock jetty, which is normally about six feet above sea level.

Two of the people yanked off the jetty required medical attention, the report said.

Within five minutes, the NOAA report said, the water returned to as it had been before.

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