This is a PDI simulation with fluids and some particles instances.
The model was created from a single photo found on the internet. Modeled with the help of Image Modeler only to place locators and get the camera FOV right.
The collapsing geo has been baked down and set to emit particles some particles instanced geo and some for emitting fluids.
The particles(green) that emit fluids during the falling also emit particles(red) on impact that have a short life span in the time they are alive they emit particles(blue) that emit more fluids to get more fluids from the collapse closer to the ground.
The geo instance particles have a few per particle random expressions. One of the expression is to grow and different rates from birth and stop growing at scale 1. I did this to stop particles from just popping in which was distracting.
The breaking up of the geo was a long process using voronoi shatter, then sub-shattering around the places where the passive building meets the dynamic parts. Keeping everything in clean named groups was a must.
The dynamic baked geo had emitter placed on them then everything was made invisible apart from dynamics and the emitters where selected and put into a Quick Selection Set and Added to the Shelf. This allowed the selection of hundreds of emitters and ability to change their values in bulk using the Channel Box.
I also added (with constrain parenting a group full of detail objects like bricks) extra jagged detail to the baked collapsing geo only to the bits of geo that where inside parts of the walls and looked very flat in the render and needed that jaggedness to create a more interesting silhouette.
As for texturing. After the geo was modeled and the UV's layed out the image was projected onto the geo, baked down and painted on top of in photoshop to get more detail into areas further from the camera. The baked texture was used as a color pallet helper.
A more detailed write up can be found here.