Fun fact a rich guy once bought the mining rights to a meteorite impact crater believing that it would be an easy source of pure iron to mine since most meteorites are primarily iron, but after digging for hundreds of feet and finding no iron the project ran out of money and went bust, because meteorites disintegrate into first a liquid iron, which then oxidised very rapidly and becomes dust and small chunks which settle in an ejecta pattern around the impact zone, sometimes many miles wide, and this thin layer is fairly quickly eroded away, so there's no usable iron nor a meaningful amount of oxide remaining.

Smaller meteorites often land intact, as their surface area allows for meaningful atmospheric friction to slow them down, and these are chunks of iron, but larger than about the size of a large van, the meteorite is usually obliterated.

Entry angle can allow for exceptions, IE if a meteorite just grazes the atmosphere but still slows down enough to suborbital speeds, it can land as big chunks, but even these get scattered over hundreds of kilometres. Any impact steeper than about 20 degrees and larger than a large van is usually carrying so much momentum at ground level that it hits at several, and possibly tens of kilometres per second, which liquifies and scatters it widely.

It's basically like setting of a nuclear explosion at that site. A big one, getting close to the Tsar Bomba. Everything nearby including the meteor turns to plasma and vapor, and that creates a shockwave that blows out everything nearby not instantly vaporized.

I'm not a craterologist but my understanding is an impact like this is going to chemically change the asteroid and the ground. So partly disentigrates and kinda becomes part of the ground (idk if that counts as under)