This is in no way an endorsement or disagreement with that mate, but for reasons that are way too boring, (pardon the pun), to explain, I have researched, (looked at Wiki) the construction of the Doha metro network. Built, obvs for the WC.
Its mostly underground, again, obvs, broke world records for the sheer number of boring machines running at the same time, and won tons of awards for its construction in the tunneling world.
And in the 6 million man hours it took to finish, not one hour was lost to a safety incident. Let alone a death.