A freak wave in Barnegat Inlet on the New Jersey Shore may have been caused by a tsunami, the National Oceanographic and Atmospheric Administration says.

The 6-foot wave June 13 knocked three people from a jetty, injuring two of them severely enough to be hospitalized, The Philadelphia Inquirer reported. The NOAA's Tsunami Warning Center said 30 gauges recorded information suggesting a tsunami, a widespread wave usually associated with earthquakes.

In most areas, the tsunami -- assuming that is what it was -- would have been barely noticed. In Barnegat Inlet, it was pulled into the narrow entrance to Barnegat Bay.

In this case, the tsunami may have had its origins in a derecho in New Jersey, a narrow storm with straight-line winds.

The Jersey Shore has had earlier experience with tsunamis. A report by a retired National Weather Service staffer, Harry Woodworth, said a 1938 hurricane that devastated New England did considerable damage in New Jersey even though the eye of the storm was far out to sea, possibly because of a hurricane-generated tsunami.