(Reuters) - A Hawaii man who had a heart attack after a false alert about an incoming ballistic missile flashed on cellphones in January has sued the state, accusing it of negligence in the incident that panicked thousands of people.

FILE PHOTO: A combination photograph shows screenshots from a cell phone displaying an alert for a ballistic missile launch and the subsequent false alarm message in Hawaii January 13, 2018. REUTERS/Hugh Gentry

James Sean Shields was driving to the beach with his girlfriend on the morning of Saturday, Jan. 13, when the state flashed out alerts onto phones across the islands: “BALLISTIC MISSILE THREAT INBOUND TO HAWAII. SEEK IMMEDIATE SHELTER. THIS IS NOT A DRILL.”

The message came at a time of rising tensions between the United States and North Korea, which had claimed it had developed a ballistic missile that could reach the U.S. mainland. It sent thousands of island residents in a panicked search for shelter before the Hawaii Emergency Management Agency recalled the message a half-hour later, saying it had been sent in error.

Shields and his girlfriend filed the lawsuit in the state’s First Circuit Court on Tuesday.

“They decided that there was not much they could do to protect themselves from this threat and decided that if they were going to die, they might as well die together on the beach,” the lawsuit said, according to a copy published by Hawaii News Now.

The lawsuit seeks unspecified financial damages.

Soon after phone calls to say goodbye to his loved ones, including his son and daughter on the U.S. mainland, Shields felt pain and burning in his chest, the lawsuit said.

The couple rushed to a hospital, where Shields’ heart stopped soon after arrival and faltered again after cardiopulmonary resuscitation. He underwent emergency surgery to save his life, the lawsuit said.

Shields’ girlfriend, Brenda Reichel, is also a plaintiff in the lawsuit, seeking unspecified damages for the emotional upset of watching her boyfriend have a heart attack and “almost die on several occasions.”

Richard Rapoza, a Hawaii Emergency Management Agency spokesman, said the agency looked forward to resolving the lawsuit “in an appropriate forum.”

“We join all the people who are wishing the best for Mr. Shields and his family,” Rapoza said.

The state’s attorney general did not respond to a request for comment.

An investigation found that the employee who sent the alarm had mistaken an alert drill for an actual attack. The employee was later fired.

The Federal Communication Commission’s investigation concluded in April that a “combination of human error and inadequate safeguards” were to blame.