It cracked because the corner for the sink was too sharp. You MUST radius all inside corners. There is no real repair to fix a high stress spot like that. It needs to be redone, with rounded corners for the sink.

It cracked because the corner for the sink was too sharp.

To me it looks like too long and deep of a crack to be caused by the sink corner (which does not look that sharp). It also happened too quickly to be caused by the sink corner radius. Given the length of the crack and how wide the crack has opened, I believe the countertop is either not supported properly, and/or was installed out of level. How is the overhang for the chairs supported?

Take a photo from that opposite side, and also provide us dimensions of the countertop length and width, and the depth of the overhang from where the base cabinet ends to the edge of the overhang.

The counter needs to be entirely replaced. The crack is too deep and wide to be fixed properly, and even if it were, the underlying issues must be cured. If the island base cabinets are out of level and/or the overhang is not properly supported, you will have the same problem again. You need to fix the underlying issues.

They think break actually started from the middle of the countertop and ran towards the sink. I think the picture makes it look like a sharper corner than it is, it’s pretty rounded. I don’t think it was the sink cut.

Fabricator thinks it’s from someone standing on it or dropped sometime on it from pendant install. I’m
Not convinced of that either. I think it’s either outta level or just a crappy slab. Looks like it’s just kinda fracturing in a few spots.

Regardless, looks like we are getting a new countertop. Hopefully not something we need to pay for. 😵‍💫 kitchen cabinet installer guy and the fabricator guy both came out and said there is no saving it.

The overhang is about 15”, huge plywood board mounted under the entire thing.

Pic to show overhang/island build for reference.

If the pendant lamps were installed after the slab, I can promise you someone crawled onto the slab during the lamp installation.

" The overhang is about 15”, huge plywood board mounted under the entire thing. "

Plywood is useless. Needs steel stretcher bars. Probably a combo of a weak psection of the slab and the useless plywood.

If the island base cabinets are out of level and/or the overhang is not properly supported, you will have the same problem again.

Yup.

Just double checked in my photos, our electric was all installed before the slab, so I can guarantee no one ever stood on this thing.

Did you see my post above?

You need steel.

I’ll ask our fabricator about steel.

If he is the guy who said to use the plywood I would look for another fabricator.