From the picture this appears to be a blowout in a post tension slab. The anchor shown should be embedded in the slab.
5-10 days after a post tension slab is poured and before it is totally cured, the contractor comes and tightens the strands/cable to within 7% of the engineers designed strength of between around 25,000 to 35,000 psi. Looks like there's concrete on the anchor here (in the pic) so it was probably stretched/tightened as needed than had a blow out. Appears that cable and anchor have been exposed for a while. The size of the hole in the slab looks about the size of the anchor, another indication of a blowout. The effects of the blowout inside were probably patched on the slab with an epoxy and  the flooring would have been redone. This could have been engineer approved or maybe not. The builder should have addressed the issue and resolved the problem with the original licensed/registered engineer that was paid to design and certify the slab in the first place. 
Also, as seen in the picture there is not the required 4" slab exposure below the stucco, which of course is even more of an issue since there is a hole in the slab. A minimum of a four inch gap is required at the base of the wall between masonry and finished grade for proper drainage and to avoid water intrusion into the exterior wall assembly.

Note: For more info on post tension slabs, visit the blog entry on this website. Click Here- 'Post Tension Slabs'.

Picture from Home Inspector Pro, submitted by David Nasser