Underground utility boxes that make a huge clanking noise when driven over.

I work for an HOA in Mountain View, California, Cantera of Mountain View. I am getting numerous complaints about the noise that is made every time someone drives over these boxes. After months of conversations with PG&E, Comcast, and AT&T, I believe these are AT&T utility boxes, and they are not properly bolted down, causing a very loud and annoying clanking sound when driven over. Please help me contact the correct department to have these underground boxes secured properly, greatly reducing the noise when driven over.