self bombardment

[admiral-bell]

on RoR I self bombarded with a fire catapult and destroyed the improvements the catapult was stationed on. Bug or feature?

 

[admiral-bell]

Description of problem - on RoR I self bombarded with a fire catapult and destroyed the improvements the catapult was stationed on.
Steps to reproduce -move fire catapult to an improved square and fire on the square it is stationed on
Observed result - tile improvements are destroyed
Expected result – see above