CHICAGO (AP) -- Dozens of friends were crowded onto a third-floor porch at a party early Sunday when the floor dropped out from under them, sending wood and bodies crashing to the ground. Twelve people died, most of them crushed on the two porches below.
At least 57 others were injured, some critically, authorities said.
"There were people covering me. It was pitch black and people were yelling, 'I'm dying.' I was assuming I was going to die," said Natalie Brougham, 22, who walked away with injuries to her hip and shoulder. "I guess I got lucky and only had two or three people on top of me."
As many as 50 people, most of them in their early 20s, had crammed onto the apartment porch for a party in the city's affluent Lincoln Park neighborhood when the floor fell at about 12:30 a.m., police said.
Seven men and five women, most of them apparently on the porches directly below, were sandwiched between the falling floors and killed, said Larry Langford, spokesman for the city's Office of Emergency Management.
"There was no warning," said Simon Rasin, a University of Chicago law student who attended the party. "I fell through both the second and the first floor decks into the basement area in just a pile of bodies."
His friend Henry Wischerath was among those killed, he said.
"There was chaos," Chicago Fire Commissioner James Joyce said. "There were people screaming and crying in the alley."
Partygoers who had been safe inside the apartment said they tried to rescue their friends from the pile of lumber and bodies, while people poured out of a nearby tavern to help.
"They were bloodied and covered in rubble, their clothes were ripped. Women were looking for husbands, men were looking for wives. It was horrible," said Geraldine Schapira, 33, who lives nearby.
Eleven people were pronounced dead at the scene, and the Cook County Medical Examiner's office confirmed that a 12th person was dead on arrival at hospital.
Hours after the collapse, red plastic cups still lined the porch's railings that hung from the third-floor walls, serving as an eerie reminder of just how fast the floor fell.
Most of the people at the party were friends in their early 20s, many of them graduates of New Trier High School in Chicago's northern suburbs, said Fina Cannon. She had been in the apartment's kitchen, looking out at the porch when it gave way.
"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."
"It was simply a case of too many people in a small space," Joyce said. He urged people to be careful about safety, particularly with the upcoming July 4 holiday.
City Building Commissioner Norma Reyes said the city had talked with the building's owner, who was in Canada. She said the city had "no indication of any structural problems or insufficiencies with the porch," and she did not know how old it was.
"Thus far, there is no evidence of any criminal activity whatsoever," Police Superintendent Terry Hillard said.
The medical examiner's office released names of 11 victims Sunday. They were identified as: John Jackson, 22, of Kansas City, Mo.; Katherine Sheriff, 23, of Chicago; Eileen Lupton, 22, of Lake Forest; Wischerath, 24, of Buffalo, N.Y.; Shea Fitzgerald, 19, of Winnetka; Muhammed Hameeduddin, 25, of Chicago; Margaret Haynie, 25, of Evansville, Ind.; Sam Farmer, 21, of Winnetka; Eric Kumpf, 30, of Hoboken, N.J.; Robert Koranda, 23, of Naperville; and Kelly McKinnell, 26, of Barrington.
Associated Press writers Shia Kapos, Maura Kelly and Don Babwin contributed to this report.