https://www.faa.gov/lessons_learned/transport_airplane/accid...
I watch a lot of airplane disasters.
TLDR: you are supposed to properly disassemble and use a proper lift to lower the engine, not shove it in with a fork lift (even though it's quicker).
I don't think this was the cause of this accident though, the engine was on fire before takeoff.
Not an airplane engineer, but I very much doubt anyone has used a forklift to install an engine since 191. Procedures got much more strict.