The state ferry Malaspina was evacuated Saturday night after a 20-year-old Oregon man was overheard making a threat to blow it up, Juneau police said.
No explosives were found and no one was injured. Police are contemplating possible criminal charges.
Police did not release the man's name. He was questioned by them at the Auke Bay Ferry Terminal. The captain of the Malaspina eventually allowed him to reboard the ship, and the man continued on his journey, Sgt. Kris Sell of the Juneau Police Department said.
"We became comfortable that he didn't have anything to fulfill his threat," she said.
The man was staying at a hotel in Haines, when he reportedly said he would blow up the Malaspina if he was not allowed to load his disabled Plymouth Neon onto the 408-foot ferry, police said. The man then made additional comments about blowing things up.
The hotel's clerk told her boyfriend, an employee on the Malaspina, and the boyfriend relayed the threats to staff at the Auke Bay Ferry Terminal, police said.
The man's Neon was towed onto the ship. The Malaspina left Haines at 11:55 a.m. on Saturday and was scheduled to depart Juneau at 7:30 p.m.
Ferry personnel evacuated the ship when it docked in Auke Bay shortly before 7 p.m. Police were notified at 7:02 p.m., and the Coast Guard also responded.
The ferry's passengers, including the 20-year-old Oregon man, were removed. The vehicles, including the man's, were searched.
Ferry personnel completed their search at 7:55 p.m., and a Juneau police bomb technician conducted a second inspection of the man's car.
The man told Juneau police he had no explosives, and denied threatening to blow up the ship.
"We're going to continue to do some research about what happened and whether or not he met the elements of the crime by making indirect comments," Sell said. "It's not quite as clear as if you were to go into the airport and say, 'I'm going to blow up this plane at this hour.' Then you have a pretty direct threat."
The Alaska Marine Highway System has increased its security measures since the government raised its maritime security to orange, its second-highest level, after the July 7 bombings in London.
Built in 1963, the Malaspina carries 500 passengers and has room for 88 vehicles.
"It's a sensitive time for anyone to be making comments about blowing up a plane or a subway or a ferry," Sell said. "It's not a comment that's going to go unnoticed."