[DocTomoe]

To give a few comparison numbers:

In Switzerland, arguably the world's experts in tunnel-boring, one death per tunnel kilometer is considered acceptable (and it is often less than that).

The much easier Channel tunnel has had around one death per five kilometer.

The Japanese Akashi Kaikyo Bridge prominently has had no construction deaths, which was considered extraordinary at the time. The Humber Bridge, which was the longest suspension bridge before Akashi Kaikyo, did cost four lives.

Construction is a dangerous business. You operate heavy machinery. You move large amounts of heavy material. You deal with power tools. Death is always a possibility - and that's something we IT folks tend to forget in our clima-controlled environments with our cozy desks and expensive chairs.