There seem to be some differences between various press reports about the exact location of the street to be potentially dug up where there had been an open roadwork trench. I found 4 possible locations
#1 is a trench which was possibly open in the public road just west of the church, this trench was for drain replacement, there was a photo in a minor local newspaper article predating May 3 but I can't find it now.
#2 and #3 are the two open trench locations which already in the published case files are described, photographed in their filled in state, and mapped. These are further north than the church but further south than the apartment.
#4 is an inspection hole reported in the files by a witness who saw the cover and surround off and placed at the side of the street on 3 May (and the witness's opinion seems to be that would be possible for someone to have fallen into the uncovered hole), but then the witness saw the cover and surround correctly in place the next day, location is at a junction somewhere near the supermarket. This being probably the closest to the apartment of the four I have listed.