TAMPA (WFLA) – Rescue workers at the site of the Surfside condominium collapse heard a woman’s voice under the rubble shortly after they responded last Thursday but were unable to find her alive, Miami-Dade Fire Rescue Chief Alan Cominsky said.

Speaking at a news conference Thursday morning held a week after the collapse, Cominsky confirmed that rescuers who were under the structure of the Champlain Towers South Condo as part of the initial search and rescue efforts could hear the woman.

“We were searching for a female voice … we heard for several hours, and eventually we didn’t hear her voice anymore,” he said.

Cominsky said the workers continued searching but never found the woman alive.

“Unfortunately, we didn’t have success on that,” he said.

Officials said as of Thursday morning 18 people have been confirmed to have died in the collapse, with more than 140 still unaccounted for.

The Associated Press contributed to this report.