While rescue efforts were still under way, a second section of the 29m (90ft) high tower began crumbling again, with bricks raining down, creating a huge cloud of dust.
The firefighters were unharmed, pausing their rescue work for a time, but then continuing their search for the missing man.
After the initial collapse, firefighters “put up some protection” around the trapped man, so when the second collapse happened, “they obviously shielded him”, Lamberto Giannini said.
“It will be a very long operation because we have to try to save the person, but we also have to try to mitigate… the enormous risks faced by the people trying to carry out the rescue,” he added.
A police chief has said there is no imminent danger that the tower will disintegrate.
