SEOUL (Reuters) – Questions mounted on Tuesday about the crash of a Jeju Air jetliner as police scrambled to identify the victims and as families of those killed in the country’s deadliest plane crash in the South Korea pressed the authorities for more information.

The National Police Agency said it is making every effort by increasing personnel and fast DNA analysts to shorten the identification time. Five bodies remained unidentified as of Tuesday.

Family members gathered at the country’s Muan International Airport, where the crash occurred, are pushing for a faster identification and more information from the authorities.

All 175 passengers and four of the six crew members were killed when a Jeju Air Boeing (NYSE: ) 737-800 landed belly-up and skidded off the end of the runway, exploding in a fireball as it took off. hit the wall. Two crew members were pulled out alive.

The acting President of South Korea, Choi Sang-mok, on Monday ordered an emergency safety inspection of the entire airline operation in the country as investigators seek to find out what caused the deadliest air disaster in South Korea.

The Transportation Ministry said representatives from the US National Transportation Safety Board (NTSB), Federal Aviation Administration, and aircraft manufacturer Boeing have joined the investigative body and plan to meet in Muan on Tuesday to discuss the future schedule.

A US team led by the NTSB is on the ground in South Korea providing assistance, board chair Jennifer Homendy said in an interview. The NTSB said in a statement that it has sent three investigators including people with expertise in operational factors and airworthiness to South Korea to help with the investigation.

“If we need more specialists we will send them,” Homendy said.

Investigators are looking into bird strikes, whether any of the aircraft’s control systems were disabled, and the apparent rush of pilots to attempt to land shortly after declaring an emergency as possible. caused the crash, fire and transportation officials said.

Officials also face pointed questions about aspects of the airport’s design, particularly a large dirt-and-concrete embankment near the end of the runway used to support navigation equipment. .

The plane crashed into the embankment at high speed and exploded into a ball of fire. Bodies and body parts were thrown in the surrounding fields and most of the planes were destroyed in the fire.

South Korean officials said the embankment was built according to standards, and that there are similar features at other airports including those in the United States and Europe.

But many experts say its proximity to the end of the runway defied best practices and likely made the crash more deadly than it otherwise would have been.

The runway design “absolutely (absolutely)” meets industry best practices, preventing any hard structure such as a berm within at least 300 meters (330 yards) of the end of the runway, it said. John Cox, CEO of Safety Operating Systems and former 737 pilot.

The airport’s concrete berm can be seen less than half the distance from the end of the pavement, according to a Reuters analysis of satellite images.

South Korean officials say it is about 250 meters from the end of the runway itself, although a paved apron extends beyond that.

The plane appeared in video footage to be slow and controlled as it exited the runway, Cox said. “If that berm had been hit that would have been a tragedy.”