This morning I was better able to see just what is going on. The cross street (Calle Popcatépetl) just a few doors from the apartment is all torn up, and it appears that they are putting in new sewers.
(I have no clue as to the meaning of "Yoccalli" written on the barricades.)
So, my usually pleasant neighborhood is a mess. I will be here for a little more than three weeks. It will be interesting to see if they complete the work in that time.