The U.S. Coast Guard is searching for a cruise ship passenger from Australia who went overboard en route to Hawaii, just 500 miles south of Kailua Kona.

“Joint Rescue Coordination Center Honolulu received a report from the cruise ship Quantum of the Seas of a man overboard at 11:03 p.m. Tuesday evening,” the coast guard said in a release. “The crew of the cruise ship remained on scene to search for approximately two hours, deploying six life rings.”

Related: A Cruise Passenger Plummeted to Their Death From a Room Balcony While Guests’ Stunned Reactions Were Captured by Vlogger

The coast guard deployed an aircrew to search for the passenger early Wednesday morning and, after hours of searching, returned to land to refuel and begin again early Thursday morning.

The Royal Caribbean Quantum of the Seas ship, which is set to dock Friday morning in Honolulu has been at sea for 15 days after departing from Brisbane, Australia.

“While on its trans-pacific sailing, a guest onboard Quantum of the Seas went overboard,” Royal Caribbean confirmed in a statement, per ABC7. “The ship’s crew immediately launched a search and rescue operation and is working closely with local authorities.”

There have been no further details released about the incident or what might have happened.

Royal Caribbean did confirm that the man falling overboard happened just days after a woman died on the ship due to a medical emergency. Both incidents are isolated as the man and the woman did not know each other.

“[The staff] started doing announcements over the loudspeaker saying ‘potential man overboard’ and that everyone had to go back to their room,” passenger Adam Gelzer told Australian outlet News.Com.Au. “I have spoken to workers who have been working on ships for years and they said they have never seen anything like this happen before.”

The incident follows a similar tragedy earlier this month when a passenger was pronounced dead after falling from the balcony in their room and landing on the deck below during a Virgin Voyages cruise headed for Honduras.