ROME (AP) — In the heart of Italy’s capital, firefighters battled to free a worker trapped for hours beneath the debris of a medieval tower that partially collapsed during renovations on Monday, leaving another worker critically injured.

The rescue operation was fraught with challenges as the unstable structure continued to crumble, complicating efforts to reach the trapped worker. Firefighters initially attempted to access him through a first-floor window, but were forced to withdraw using telescopic aerial ladders amidst a cloud of dust. A subsequent attempt using two ladders was also abandoned, prompting the deployment of a drone to assess the situation.

As nightfall neared, firefighters employed cranes to maneuver large tubes, vacuuming debris from a second-floor window to clear the path to the trapped individual.

Following the midday collapse, three workers were successfully rescued without injuries, according to firefighter spokesperson Luca Cari. However, Italian media noted that another worker, aged 64, was in critical condition in the hospital, though his current status remains unknown. Fortunately, no firefighters have been harmed during the ongoing efforts.

Lamberto Giannini, Rome’s chief law enforcement official, reported “signs of life” from the trapped worker. Firefighters had managed to provide him with some protective covering in an earlier rescue attempt.

Giannini described the scenario as “very complex” and mentioned that additional equipment was being brought in to aid the rescue mission.

“It will be a very long operation. We must try to save this person while mitigating the enormous risks to the people who are trying to save him,” Giannini told reporters.

Hundreds of tourists had assembled to watch as firefighters used a mobile ladder to bring a stretcher to the upper level of the Torre dei Conti during the first rescue attempt. Suddenly, another part of the structure partially collapsed, sending up a cloud of debris and forcing firefighters to quickly descend on the ladder.

Queen Paglinawan was working in a nearby gelato parlor when she heard the two loud noises from the town in quick succession.

“I was working and then I heard something falling, and then I saw the tower collapse in a diagonal way,” Paglinawan, 27, said as yet another collapse occurred in the background.

German student Viktoria Braeu passed by the scene just as the partial collapse during the firefighters’ rescue occurred.

“We were just at the Colosseum … and we were just walking to get some food. … And then we were like, ‘It’s probably not long until it’s going to go down,’ and then it just started erupting,” said Braeu, 18.

The Torre dei Conti was built in the 13th century by Pope Innocent III as a residence for his family. The tower was damaged in a 1349 earthquake and suffered subsequent collapses in the 17th century.

Rome Mayor Roberto Gualtieri and Italian Culture Minister Alessandro Giuli were at the scene, but did not speak to reporters.

“The firefighters risked their lives with the second collapse. We are worried for the worker who remains trapped,” said Federico Mollicone, chairman of the parliamentary culture committee.