Could be SA-15. In 2005/6 Iran acquired them. Thought it more logical to be SA-6.
The engines looked to be in good shape from the imagery shown thus far. So, I can't see anything causing an uncontained engine failure/fire. Look at the blades, they are all there. Also, look at the kinetics of the engine. That big of a mass is not even disfigured.
I would not be surprised if Iran doesn't start washing all of the pieces with soap and water to get explosive residue off the parts/pieces.
The small rods from the explosive war head should still be evident and easy to notice.
The explosive is easy to detect.
What will be interesting is if our RJ's and other assets picked up a scrum half radar going into high PRF. What these Iranians don't realize is lots of electronic vacuum cleaners out there snorting up electrons and identifying purpose and location of those trons.
Wreckage spread out. Lots of small tiny fires. No "smoking hole". wreckage impact was fairly flat. Not fan shaped and not vertical.