Police raid Jeju Air offices after crash that killed 179 in South Korea; the executive director of the airline company is prohibited from leaving the country

South Korean police raided the offices Jeju Air and the operator of Muan International Airport on Thursday as they step up investigations into the fatal accident a Boeing 737-800 which killed 179 people.

He carried the flight 181 passengers and crew from Thailand to South Korea on Sunday when it made a distress call and landed on its stomach before hitting a barrier, killing all but two flight attendants on board.

On Thursday, authorities conducted search and seizure operations at Muan Airport where Flight 2216 crashed, the regional aviation office in the southwestern city and Jeju Air’s office in the capital Seoul, police said.

Jeju Air CEO Kim E-bae has also been banned from leaving the country while the investigation continues, police said separately.

“The police plan to quickly and rigorously determine the cause and responsibility for this accident in accordance with the law and principles,” the police said in a statement sent to AFP.

At Muan Airport on Thursday, soldiers, police and investigators in white suits were still examining the crash site, while orange-robed monks held prayer ceremonies nearby.

Inside the airport, the stairs were covered with colorful sticky notes left by mourners.

“Honey, I miss you so much,” one of them said.

“Even if you have faced lonely and painful moments in death, may you now soar like a butterfly,” read another.

Relatives also left flowers and food near the crash site, including tteokguk – a rice cake soup traditionally enjoyed in South Korea on New Year’s – as they said their goodbyes, many in tears.

Star chefs featured in Netflix’s megahit cooking competition show “Culinary Class Wars,” including Ahn Yu-seong, joined volunteers in Muan this week to prepare meals for the victims’ families.

And people across the country paid in advance remotely for coffee at an airport cafe so families of the victims, who had been camped out in a lounge since Sunday waiting for news, could drink for free.

More bodies were released to families on Thursday to prepare for funerals, the country’s ministry said.

Officials first pointed to a bird strike as a possible cause of the crash, then said the probe was also examining the role of the concrete barrier at the end of the runway.

Dramatic video shows the plane colliding with it before bursting into flames.

Yonhap reported that the warrant for Muan Airport was granted over allegations of professional negligence resulting in death, citing officials.

“Police are securing evidence related to the legitimacy of the airport’s localizer,” Yonhap said, referring to the concrete wall at the end of the runway that houses the antenna array.

They are also seeking records of communications between the control tower and the pilot just before the plane went down, it added.

Airports across the country are being inspected to check for other similar locators, the land ministry said in a statement.

Some experts suggest that the disaster might have been less deadly if the installation had not been made of concrete.

“The key to unlocking this mystery”

South Korea also announced it would inspect all Boeing 737-800 planes operated by its carriers, with a focus on the landing gear, which appeared to have malfunctioned during Sunday’s crash.

South Korea’s acting president, Choi Sang-mok, said Thursday that “immediate action” must be taken if the probe reveals any problems with the aircraft model.

Authorities previously said 101 planes of the same model were being used by six different airlines.

“Since there is great public concern about the same aircraft model involved in the accident, the transport ministry and relevant agencies must conduct a thorough inspection of operational maintenance, education and training,” Choi said on Thursday.

The crash is the worst aviation disaster on South Korean soil.

South Korean authorities have completed initial data extraction for the cockpit voice recorder, but the flight data recorder was damaged and was to be sent to the United States for analysis, officials said Wednesday.

Investigators say it was not possible to locally decode the damaged flight data recorder, which is missing a key connector, BBC News reported.

“I think the cockpit voice recorder, if I can read it, will be key to unlocking this mystery,” Robert Sumwalt, former chairman of the NTSB, told CBS News.

Jeju Air said the crash was not due to “any maintenance issues,” according to South Korean news agency Yonhap and aviation expert Geoffrey Thomas he told BBC News that South Korean airlines are generally considered to follow “industry best practice” and that both the plane and Jeju Air had an “excellent safety record.”