M135i Water damage

I just drove through some water right behind a Renault sandero and my M135i died. The Renault ahead of me drove through just fine, my engine died and wouldn’t start again. The electronics are fine, everything works but it won’t start. How worried should I be??? The car was towed by Bmw and it’s still under motorplan. Will the warranty cover it? Will I need a new engine? How bad could the damage be?