Thirteen young people, mostly in their 20s, died in the June 29 collapse in a trendy Chicago neighborhood.
The city's Office of Emergency Communications said there were more than 20 calls in the first three minutes after the collapse.
Some of the calls were from partygoers and others came from neighbors.
Some callers talked with dispatchers about how crowded the porch was with people.
Copies of the 9-1-1 tapes were released Monday.