SEOUL - The senior engineer on the South Korean ferry that sank last week said Thursday he was unaware of any problems with the ship's engine or ballast when it ran into trouble.
The 6,825-tonne Sewol, which capsized with 476 people on board, had 29 crew including captain Lee Joon-Seok.
Twenty of them escaped the ferry and have been condemned for leaving hundreds of passengers - mostly high school students on a school trip - trapped in the ship.
Lee and six crew members have been arrested and four others are in police custody and expected to be formally charged soon.
These four, including the engineer, were paraded with their heads bowed and hiding their faces before TV cameras on Thursday.
"I did not see any signs. There were no problems," the first engineer said when asked if there were any technical issues with the engine or the ship's ballast tanks.
There have been reports that the ferry did not take on sufficient ballast to counter its cargo weight.
The ship capsized after executing a sharp turn, which some experts believe triggered a shift in the cargo and caused the vessel to list beyond a critical point of return.
The engineer said he and six other crew members - who were on the third deck - had evacuated the ship "right before it sank".
Another crew member wept and said she was "very sorry" for the families of the victims and the missing.
"What I did was really wrong. I am sorry," she said.
The four face charges ranging from criminal negligence to violations of maritime laws requiring crew to ensure passenger safety before evacuating.
The confirmed death toll on Thursday stood at 169, but 133 were still missing as dive teams searched in near pitch-black conditions for bodies trapped in the ferry's interior.