It's been reported that when the accident occurred, the onboard announcement to the passengers was to stay where they were without giving any specific directions.
The same announcement was known to have been heard repeatedly for one hour before they finally told all the passengers to jump into the sea with their life vests on, as the ferry was going to sink.
Many say the delayed warning to get off the ferry could have caused a bigger tragedy as many passengers heeded instructions and stayed in their rooms, and were later unable to escape as the vessel went down.
"A female voice informed us of the situation through a speaker. She said the rescue workers would come soon and she told us to stay put."
The Sewol is one of the biggest ferries in Korea and most of the equipment is electric, including the doors and gates inside.
Some experts speculate the generator may have gone off when the ferry began to tilt to the left.
"It's highly likely the power cut off as the ferry tilted. There could have been a total blackout meaning doors would not open."
Even if the doors were open, the steep incline of the floors may have made escape much more difficult for people trapped inside.
"Many people were screaming as the floors inclined and all the equipment and people slid down."
The worst scenario is that, if there are still people trapped in the cabin, there won't be enough air for them to breathe.
Everyone is praying with all their hearts that this won't be the case and that all those unaccounted for will be rescued safely.
Sohn Jung-in, Arirang News.