Updated July 6, 2021 at 6:25 PM ET

Crews searching the building collapse site in Surfside, Fla., have discovered four more victims since Tuesday morning, bringing the death toll to 36, according to local officials at an afternoon press conference.

Authorities have identified 29 of the bodies. There's uncertainty about the exact number of people in the building when it collapsed nearly two weeks ago; officials said on Tuesday afternoon that there are reports of 109 people who were unaccounted for, but they had only been able to confirm that about 70 of those people were in the building at the time.

"People call anonymously. People call and don't leave return phone numbers. People call with partial information, not enough to really secure whether that person may or may not have been in the building," Miami-Dade County Mayor Daniella Levine Cava told reporters on Tuesday morning.

Some of the reports of possible victims are also incomplete, she said, including a name but no apartment number or no date of birth.

Levine Cava urged people who are missing loved ones to communicate with local authorities. She said there may also be victims of the collapse who have not been reported missing.

During the afternoon briefing, Levine Cava said that crews had to pause the morning's recovery efforts because of lighting and high winds, but they have since resumed. Efforts had also stopped briefly overnight due to lightning from a passing storm. Surfside Mayor Charles Burkett said the storm's winds were hampering the cranes moving heavy debris from the collapse site.

Lt. Gov. Jeanette Nuñez said Florida has declared a state of emergency ahead of Tropical Storm Elsa, which is expected to reach hurricane strength before making landfall Wednesday morning on the state's west coast.

Copyright 2021 NPR. To see more, visit https://www.npr.org.