At least nine firefighters and rescue workers were killed in Buenos Aires Wednesday when the wall of a warehouse engulfed by flames collapsed on top of them, officials said.
Authorities said the dead included six members from a federal police firefighting unit, a volunteer firefighter and two members of Argentina's civil guard.
Security Secretary Sergio Berni told reporters at a press conference at the scene that rescuers were continuing to look for additional victims in the building's debris.
Serni said several other first responders who were badly injured in the accident were "fighting for their lives."
Emergency workers who arrived to aid those crushed under the debris "found a lot of bodies covered by rubble, some with multiple serious injuries," said Alberto Crescenti, head of the public medical service.
"Unfortunately, most of the victims died at the scene," he said.
"We tried to get them out, but that was impossible," he told reporters.
One grieving civil guard officer at the scene said he was devastated by the loss of his comrades.
"What happened to us is a terrible tragedy that never should have occurred," he said.
"We are sad -- and angry. We work for next to nothing, but nevertheless put on a brave face," he said, adding that under such conditions "we just can't continue."
Officials said they do not know what caused the blaze in the 19th century-era building.
Contrary to earlier statements, officials said they could not say with certainty that the building was unoccupied when the blaze erupted.
The wall fell as firefighters were using an electric saw to cut through a huge iron gate at the warehouse, which housed archival bank records.
The tragedy occurred in a neighborhood of businesses and modest single family homes in southern Buenos Aires.