Amazon: Bent Push Rod

[ColoradoAmazon]

I purchased a 1962 121 that came with a rebuilt B18 engine. The previous owner installed the engine but never completed the installation or ever fired the engine.

I have completed the installation and have run the engine. The engine initially ran fine but started running rough. I discovered cylinder #1 had no spark and was really low on compression. I removed the valve cover and discovered the intake push rod on cylinder #1 was bend and is stuck in the head.

I'm a novice when it comes to engines so I'm looking for some input.

1 - How does something like this happen? (wondering if the valves were not adjusted properly. Some of the other push rods are loose)?
2 - I'm thinking I need to remove the rocker shaft, pull out the bent push rod, install a new push rod and adjust the valves.

Any input on what caused this and how to remedy would be greatly appreciated. Thank You!