Naver Corp. and Kakao Corp. opened online spaces to mourn the deaths of more than 150 people in a crowd crush that occurred Saturday evening in Itaewon, central Seoul, as some 100,000 people packed the nightlife district to celebrate Halloween.

Naver placed an “Itaewon accident” tab next to the search box of its main page, where people can access related news, report missing persons or express condolences by clicking on a “black ribbon” button.

Users cannot leave any messages, a measure to prevent possible secondary damage to the victims. More than 350,000 Naver users “wore” the black ribbons online as of 2 p.m. on Monday.

Kakao placed a tab on its messenger KakaoTalk that links to a page for mourning. By tapping on the “see more” button on the bottom right of the KakaoTalk app, one can see a tab for mourning under Kakao Now.

Users can leave set messages of condolences, but cannot write anything else. Kakao said this was to prevent possible secondary damage to the victims.

The nation’s retailers, which called off all Halloween-themed marketing events on Sunday, went on to announce the cancellation of more promotional events on Monday.

Shinsegae Group canceled its major “Korea SSG Day” annual sale which was scheduled to run for 12 days from Nov. 11 with 19 affiliates taking part. The retailer had planned a longer than usual sale as it acquired G-market this year.

An opening ceremony for the Korea Sale Festa, the Korean equivalent for Black Friday, was also called off on Monday.

With some 2,500 retailers, manufacturers and service providers participating, this year’s Korea Sale Festa, which runs from Nov. 1 through 15, will be the largest-ever annual shopping event in South Korea.

An opening ceremony was slated to be staged in front of the Myeong-dong Art Theater in Seoul on Monday, but the planning committee for the shopping event said it has decided to call it off out of respect for the victims of the Itaewon tragedy and the bereaved families.

Department stores also postponed their Christmas events. The Hyundai Seoul in Yeouido had begun a daily lighting show featuring 6,000 lights, a 13-meter Christmas tree and 120 smaller ones last Friday, but stopped lighting the trees after the Itaewon disaster.

Lotte Department Store put off its plan to unveil its Christmas decorations this Thursday.

The government designated this week as a national mourning period after at least 154 people were killed and 139 were injured in the crowd crush on Saturday.

(sophie@heraldcorp.com)