It's also probably not the work crew's fault, nor most of Comcast's. Specs and city plans can be inaccurate, underground lines can drift over time, and it's hard to get an accurate reading below concrete without, well, digging. I'm assuming they used their best judgment on this and only knew it was a problem after they struck the line.
Comcast probably had to haggle with the city to run a single line. Typically there's redundancy in these systems, so the fact there wasn't here is... a thing.
@Leviamicky Yeah, I'd assume they tried to do so here and either didn't find it or discovered that fiber doesn't scan like power lines do?
@Goldkin normally they scan for cables/services and dont trust the maps.... dont they? (they do that here)