A South Korean passenger car ferry ran aground Wednesday night off the southwestern coast, prompting a criminal investigation by the Korea Coast Guard. The agency alleges that the first officer was distracted by his mobile phone, leading to a series of critical errors.

The ferry, Queen Jenuvia II, was en route from Jeju Island to Mokpo when it deviated from its course in a narrow channel and struck an uninhabited islet near Jokdo, part of Shinan County in South Jeolla Province. The vessel carried 246 passengers and 21 crew members, all of whom were safely evacuated.

According to the Coast Guard, the first officer initially reported a steering problem, but later admitted he had been reading news on his cell phone while at the helm. During a critical stretch of the voyage, the ferry remained on autopilot when, according to standard safety practice, it should have been navigated manually.

Because of the distraction, the ferry missed the correct moment to turn and veered off course by roughly 2.9 kilometers — ending up perilously close to the island with part of its hull striking land. The impact caused a hull breach, according to coast guard reports.

Investigators say the first officer and one of the helmsmen, who is Indonesian, are being detained on suspicion of gross negligence. Evidence collected for the investigation includes the officers’ mobile phones, voyage data recorder information, and CCTV footage from the ship. The master of the vessel, a Korean national in his 60s, is also under scrutiny for being absent from the bridge at the time of the incident.

The ferry was refloated during high tide and towed to Mokpo by early Thursday morning. Of the passengers, 27 were treated for minor injuries, including headaches and back pain. The operator, Sea World Express Ferry Co., has suspended its service on the route and issued a formal apology to those affected, pledging to restructure its safety management procedures.

Coast Guard officials emphasized that the stretch of water where the incident occurred is typically navigated manually because of its narrow and complex nature. They plan to press criminal charges, citing “clear negligence” by the crew.

The grounding has sparked concern over adherence to safety protocols, especially in light of South Korea’s maritime accident history.