Rescuers at the site of the Florida condo collapse heard a woman's voice during their initial search and rescue operations.

Miami-Dade Fire Rescue Chief Alan Cominsky confirmed the incident in a news conference on Thursday morning, July 1, NBC 6 South Florida reported.

Cominsky noted that rescuers under the Champlain Towers South Condo's structure could hear the woman's voice in the early hours after the condo collapse. However, he said they were unable to find her alive.

"They were searching for a female voice, is what we heard for several hours, and eventually we didn't hear her voice anymore," Cominsky said.  He noted that the workers continued to search, but "unfortunately" they never found the woman alive.

Despite their failure in locating the woman who cried for help, the fire rescue chief stressed that they are trying to do the best they can do in the search and rescue operations.

As of Thursday morning, officials said 18 people had been confirmed dead in the Florida condo collapse, with 145 people still unaccounted for.

RELATED ARTICLE: Florida Building Collapse: Puerto Rican Artist and Costa Rican Accountant Among 18 Dead; Many Latin Americans Still Missing

Florida Condo Collapse: Search Resumes

The search and rescue efforts resumed in Florida condo collapse on Thursday evening after it was halted in the morning of the same day over fears of another fall down would occur. 

Miami-Dade Fire Rescue confirmed that the operations in the building halted for at least 15 hours, then resumed after the recommendation of structural engineers, CBS News reported.

The pause in search and rescue operations happened after engineers detected that a large column in the portion of the building that was still standing moved at least six to 12 inches.

First responders were reported to move quickly out of the area after the reports of cracking sounds. Cominsky noted that they had monitored three "that signal that there was an expansion or whichever with those cracks."

Due to the potential fall hazards at the site of the Florida condo collapse, Miami-Dade County Mayor Daniella Levine Cava said crews are planning for the "likely" demolition of the building that collapsed while the search and rescue continues.

President Joe Biden Meets With Families of Florida Condo Collapse Victims

President Joe Biden on Thursday encouraged the victims' families to "never give up hope" as he privately spoke with those who grieved after the tragic incident near the site of the condo tower in Surfside, Florida with Fri, Associated Press reported.

"The people you may have lost - they're gonna be with you your whole life," Biden said, adding that the people who met their demise in the incident would be a part of their families' soul and a part of who they are.

Joe Biden spent more than three hours privately speaking to the families, then moved to every family to listen to their stories. 

The president talked about wanting to switch places with a lost or missing loved one and noted that "the waiting is unbearable."

Together with First Lady Jill Biden, Joe Biden personally sympathized with the families a week after the Florida condo collapse.

READ MORE: Florida Building Collapse: Grandson Says He Receives Mysterious Calls From Missing Grandparents' Landline

WATCH: Fire Chief Describes Unsuccessful Attempt to Rescue Woman From Florida Building Collapse - From FOX13 Tampa Bay