A helicopter collision with a high-rise building in Seoul has reignited a decade-old controversy over the safety of a new skyscraper under construction in Seoul.

The 123-story Lotte World 2 Tower was put at the center of debate on Monday with concerns growing over the safety of air transport flying across the city’s rising skyline.

Rep. Lee Hye-hoon of the ruling Saenuri Party said that the 555 meter-tall skyscraper project must be reviewed or the number of floors should be readjusted for public safety.

“The Lotte Tower has already been given a construction permit but the issue of readjusting the number of floors in the building must be reviewed for the sake of the public safety and national security,” she said at the party’s supreme council meeting.

Measures to suspend construction also need to be discussed until the government comes up with better ideas to improve the safety of Seoul skies, she added.

Later in the afternoon, Lotte Group said that it cannot accept the demand to modify its construction plan.

“The plan to construct a 123-story, 555-meter-tall building has been approved. Therefore, (the issue of) readjusting the number of floors is not a matter to consider,” the group said in a statement.

Safety concerns have grown rapidly after the private helicopter owned by LG Electronics hit an IPARK apartment building in Samseong-dong, one of the city’s affluent business-residential areas on Saturday, then crashed to the ground.

The chopper crash killed the two pilots on board, but no casualties on the ground have been reported.

It was the first time a helicopter crashed into a building in Korea.

The accident sparked concerns about Lotte Tower, which is expected to be three times taller than the IPARK apartment building. If completed in 2016, the new skyscraper will become the world’s sixth highest, officials said.

Concerns have been raised for many years as the construction site is located only 5-6 kilometers from an air base in Seongnam, Gyeonggi Province.

The Air Force has opposed the project, saying pilots may be distracted by the unusually high building when approaching the airport.

Despite concerns, Lotte Group gained a final permit from the Lee Myung-bak government in 2011, on the condition the airport’s landing strip would be moved slightly.

Experts, however, have criticized the deal, saying it was not enough to fully secure flight security.

“The risk of collision has been brought up but was then ignored,” Rep. Lee said. The lawmaker quoted experts’ comments that even if the runway is relocated, it will be difficult for pilots to keep a safe distance.

The government commenced with a full investigation into the helicopter accident on Sunday. Investigators are likely to focus on whether or not the helicopter lost visibility due to heavy fog as well as whether the pilots were pressured to operate the chopper in poor weather.

The helicopter left Gimpo International Airport at around 8:46 a.m. and headed to LG’s Jamsil heliport to pick up company executives and transport them to Jeonju on a business trip, according to company officials.

The police have reportedly secured a list of phone conversations between the chief pilot and an LG official, to find out the truth between the contrasting testimonies.

The pilot’s son said he heard his father suggesting that the company officials take off from Gimpo, citing a heavy fog. But LG said it was the pilot’s own decision to head to the company’s Jamsil heliport to pick up the passengers.

The government said it will conduct safety inspections of high-rise buildings and choppers. A private operator of a helicopter tour in Seoul said Monday that it will temporarily suspend its business due to increased concerns about the safety of air transport.

By Cho Chung-un (christory@heraldcorp.com)