Workers inject reactive chemicals to consolidate the construction site of the new 25.5-kilometer Metro C subway main hub in Piazza Venezia in central Rome, Thursday, May 23, 2024. During a tour Thursday of the construction site at Piazza Venezia, chief engineer Andrea Sciotti said works on the nearly 3 billion euro project, considered one of the most complicated in the world, were running at pace to be completed by 2034. In the background the Unknown Soldier monument. (AP Photo/Domenico Stinellis)

A view of the construction site of the new 25.5-kilometer Metro C subway main hub in Piazza Venezia in central Rome, Thursday, May 23, 2024. During a tour Thursday of the construction site at Piazza Venezia, chief engineer Andrea Sciotti said works on the nearly 3 billion euro project, considered one of the most complicated in the world, were running at pace to be completed by 2034. (AP Photo/Domenico Stinellis)

A view of the construction site of the new 25.5-kilometer Metro C subway main hub in Piazza Venezia in central Rome, Thursday, May 23, 2024. During a tour Thursday of the construction site at Piazza Venezia, chief engineer Andrea Sciotti said works on the nearly 3 billion euro project, considered one of the most complicated in the world, were running at pace to be completed by 2034. (AP Photo/Domenico Stinellis)

A giant hydro-milling machine rests inside the construction site of the new 25.5-kilometer Metro C subway main hub in Piazza Venezia in central Rome, Thursday, May 23, 2024. During a tour Thursday of the construction site at Piazza Venezia, chief engineer Andrea Sciotti said works on the nearly 3 billion euro project, considered one of the most complicated in the world, were running at pace to be completed by 2034. (AP Photo/Domenico Stinellis)

A view of the construction site of the new 25.5-kilometer Metro C subway main hub in Piazza Venezia in central Rome, Thursday, May 23, 2024. During a tour Thursday of the construction site at Piazza Venezia, chief engineer Andrea Sciotti said works on the nearly 3 billion euro project, considered one of the most complicated in the world, were running at pace to be completed by 2034. (AP Photo/Domenico Stinellis)

A view of the construction site of the new 25.5-kilometer Metro C subway main hub in Piazza Venezia in central Rome, Thursday, May 23, 2024. During a tour Thursday of the construction site at Piazza Venezia, chief engineer Andrea Sciotti said works on the nearly 3 billion euro project, considered one of the most complicated in the world, were running at pace to be completed by 2034. (AP Photo/Domenico Stinellis)

A view of the construction site of the new 25.5-kilometer Metro C subway main hub in Piazza Venezia in central Rome, Thursday, May 23, 2024. During a tour Thursday of the construction site at Piazza Venezia, chief engineer Andrea Sciotti said works on the nearly 3 billion euro project, considered one of the most complicated in the world, were running at pace to be completed by 2034. (AP Photo/Domenico Stinellis)