A section of Rome’s 13th-century Torre dei Conti, located near the Roman Forum, collapsed on Monday during renovation work, seriously injuring at least one worker, Italian media reported.
Firefighters rescued three workers while another remained trapped inside as more debris fell during the operation.
Hundreds of tourists witnessed the scene as emergency crews rushed to secure the site.
The historic tower, built by Pope Innocent III and long prone to structural damage since a 1349 earthquake, drew visits from Mayor Roberto Gualtieri and Culture Minister Alessandro Giuli.