A man involved in planning a concert that ended in tragedy in South Korea on Friday has been found dead in an apparent suicide, police say.
Sixteen people died and 11 were injured when a ventilation grate collapsed during the concert in Seongnam.
The 37-year-old man, identified as Mr Oh, worked for one of the sponsors and handled safety measures, officials say.
He is believed to have jumped from a 10-storey building near the venue after being questioned by police.
The body of Mr Oh, an employee of the Gyeonggi Institute of Science and Technology Promotion, was found early on Saturday morning, city spokesperson Kim Nam-jun said.
Officials say he left a note to his wife which reads: "I am sorry for the dead victims. Please take a good care of my children."
Police have questioned 15 others in relation to the incident, including employees of the local online news service who organised the event, South Korea's Yonhap news agency reported.
The crowds had been watching an outdoor performance by pop bands when the ventilation grate collapsed.
Those standing on it to get a better view fell 10m (33ft) into an underground parking area.
Several of the victims are being treated for life-threatening injuries and Mr Kim has warned the death toll may rise.
About 700 people were at the concert, part of a local festival.
The BBC's Steve Evans in Seoul says the accident may intensify a debate in South Korea about safety standards.
After the Sewol ferry sank six months ago, with the loss of more than 300 lives, many alleged that the country's regulations had not kept pace with its rapid economic development.