NEW: Prime minister inspects scene of deadly tragedy
Sixteen dead after falling into a ventilation shaft at South Korea concert
Task force: Victims plunged four stories to their death when grate collapses
Eleven people were injured, three seriously
South Korea’s prime minster toured the scene of the latest deadly tragedy to befall the Asian nation Friday in Seongnam, south of Seoul.
Video of the scene showed Chung Hong-won, along with rescue officials, inspecting the gaping, cement hole that swallowed up concertgoers as they were standing on a ventilation grate that suddenly gave way.
More than two dozen people plunged some 20 meters (about 66 feet), or four stories, into an underground parking structure below. Sixteen of them died, according to a government accident response task force.
Eleven other people were injured, three seriously, the task force said.
The Yonhap News Agency reported 12 people were killed at the scene, two others died en route to the hospital, and “others may have passed away while receiving medical treatment.”
The injured were taken to four hospitals, Yonhap reported, near the Pangyo Techno Valley, the multipurpose venue where the incident occurred.
Some media reports indicate the victims were standing on the grate in order to get a better view of the stage.
A witness told CNN affiliate YTN, “There was a sudden, loud screaming and when I turned, it looked as if people were being sucked down into a hole.”
About 700 people were attending the concert, which featured South Korean artists, including the popular all-female group 4Minute, Yonhap reported.
A ferry sinking last April killed more than 300 people, many of them schoolchildren, and caused nationwide outrage.
Critics contend safety measures and regulation are not keeping pace with the fast-paced economic development in the country.
CNN’s K.J. Kwon contributed to this report.