EMOTIONAL RETURN: Back to school for survivors in S. Korean ferry disaster

ANSAN, South Korea (CNN) -- They left school two weeks ago on a field trip with hundreds of classmates.

They came back Wednesday without the scores of students who died at sea.

About 70 survivors from the sunken South Korean ferry visited a memorial at the Danwon High School in Asnan -- the high school that sent 325 students on a field trip to Jeju Island.

Inside the hallways, it didn't take long for the tears to flow. Many students sobbed as they walked past images of their classmates and hurried back onto waiting buses.

For these students, school will never be the same.

Losing hope

The ferry, en route from Incheon to Jeju, sank April 16 on the country's southwest coast.

Any hope for survivors largely hinged on the possibility of air pockets within the sunken ship, which was carrying 425 people.

Hundreds of relatives camped out near a harbor in Jindo, waiting for news. But after officials said there were no more air pockets, the grim reality set in.

"All we are asking for is bring the dead bodies out," a father wailed Tuesday. "We know they are not alive now."

Lots of blame, no answers

As the web of blame widens, even the country's president is apologizing for the disaster that has killed at least 213 passengers. Another 89 people are missing, the South Korean coast guard reported early Thursday.

"I am losing sleep as there is no news about saving more lives and because there are many families who don't know whether their loved ones are dead or alive still," President Park Geun-hye said Tuesday.

"I am at a loss for words for an apology that can be enough to console the pain and suffering even for a little while over insufficiency in efforts made to prevent the accident and also in the initial response to the accident," she added.

"We'll fix the problems and change our practices so we'll have safer nation and won't let them die in vain," Park said.

South Korean authorities arrested have arrested three people on suspicion of destroying evidence connected to the ferry sinking. Investigators also raided a Coast Guard office in a probe of how officials handled the first emergency call from a passenger.

The director and two other people with the Korea Shipping Association's Incheon office were arrested and accused of destroying evidence related to the probe of Chonghaejin, the company that owns the ferry.

The Korea Shipping Association is a trade group that promotes the interests of the country's shipping industry.

The site raided was the Coast Guard building in Mokpo, which includes the South Jeolla province emergency center -- a facility that provides 119 services, akin to the 911 emergency service in the United States.

Investigators are looking into possible dereliction of duty.