The chief mate and helmsman who were in charge of a passenger ferry that ran aground off the country’s southwestern coast this week have attended their pretrial detention hearing.

Appearing at the Mokpo branch of the Gwangju District Court on Saturday, the chief mate said he was sorry for causing harm to so many people, especially the expectant mothers aboard the ferry.

The chief mate, who was allegedly looking at his smartphone at the time of the accident, was asked if he ever used the automatic navigation system and said he only turns it on when traveling in a straight line.

The two face charges of causing injury by gross negligence after the Queen Jenuvia II ran aground off the coast of Sinan on Wednesday night, carrying 246 passengers and 21 crew members.

The Coast Guard has also opened an investigation into the ferry’s captain, who was taking a break in his office despite having a duty to command the vessel’s operation as it was traveling through a narrow passage.

No one was seriously injured in the accident.