Rescue workers at the Surfside condo tower site heard a woman’s voice in the rubble in the hours after the collapse but did not find her, said Miami Rescue Chief Alan Cominsky in a press briefing Thursday morning. “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. “Unfortunately we didn’t have success with that.” As of Thursday morning, the bodies of 18 victims have been recovered while more than 140 remain missing in the rubble, NBC 6 reports. Rescue efforts at the South Florida site were halted early Thursday as local officials fear that the rest of the structure may collapse after rescue workers recalled hearing noises from the building and sensors went off, leaving them to fear it may be moving. Cominsky thanked rescue workers for their continued work at the site as they remain on stand-by. “Everyone that’s here on scene trying to do the best we can in these heroic efforts,” Cominsky said.