Tell me of a single major conflict that didn’t involve civilian casualties. I will wait. It is terrible, but unavoidable, especially given the circumstances that Russia has created in Ukraine, unprovoked.
There are major differences between the participants with regards to intent. Intent of their actions. Russian soldiers have raped, tortured and executed civilians. There have been mass graves found in the liberated territories.
I don’t see how you can equate these with the destruction of a bridge that is vitally important to Russia’s control and supply of Crimea and southern Ukraine. The intent would be to deprive Russia of re-supply and access. The intention of mass killings, torture and rape, is to kill and torture people. There is no legitimate strategic objective for these actions.