At least 12 young people died and as many as 35 were injured early today when a second-floor balcony on an apartment building in Chicago collapsed during a party.
It is thought dozens of people may have been standing on the balcony when it gave way shortly after midnight (7 a.m. Irish time). It crashed onto the first-floor balcony below sending piles of debris to the ground, trapping people in a basement stairwell, authorities said.
"There was chaos," Chicago Fire Commissioner Mr James Joyce said of the scene that greeted the first emergency workers to arrive.
"There were people screaming and crying in the alley."
Eleven people were pronounced dead at the scene and 35 others were taken to area hospitals, he said.
The Cook County Medical Examiner's office later confirmed that another person was pronounced dead at Advocate Illinois Medical Centre.
The collapse happened in the Wrigleyville neighbourhood on the city's North Side.
"It was simply a case of too many people in a small space," Joyce said.
Ms Fina Cannon, a young woman who was at the party, said a large number of people had been on the second-floor balcony, and others were on the first-floor balcony.
All the guests were in their early 20s, and many had graduated several years ago from New Trier High School in Chicago's northern suburbs, she told Chicago cable television station CLTV.
"All of a sudden I saw all these heads going down," Cannon said. "The floor just dropped out from underneath them. They all went down in unison."
Fire Commissioner Joyce issued a message of caution about safety during Chicago's annual Gay Pride Parade, which is scheduled to take place later today in the same general neighbourhood.
"It's a tragic case of overloading," he said.
Officials are concerned the parade could lead to similar situations. Chicago Police said as many as 40 or 50 people might have been on the balcony at the time of the collapse.
Witnesses said the rails of the second-floor balcony were still in place several hours after the collapse, but the floor had fallen out completely.
Neighbours said they saw emergency workers using chain saws to cut through the debris to get to the victims.
AP