From "The Analyst":

TU-160 BOMBER FACTORY BADLY DAMAGED

Ukraine managed to hit and severely damage the building that produces the Tu-160 Strategic Bomber, at Kazan. The Tu-160 was restarted in 2018 after years of zero production. So far only one has been delivered but more are coming.
The existing fleet was also being overhauled and refitted with modern avionics.
The site is also responsible for the build of the Tu-22M3 (NATO called it the Tu-26 Backfire originally, the original NATO designated Tu-22 was the Blinder). Both of these carry the missiles that have been devastating Ukrainian energy production.
There is no other facility in Russia capable of production of such aircraft. The attack seems to have gone through the roof - just a standard large hanger type of construct with no special features. It would almost certainly have fallen through and damaged a production area and likely took a new aircraft or two out with it.
The fact that Ukraine can reach these places and bring the war so deep into Russia seems to shock the locals who witnessed the daytime attack.

Slava Ukraini 🇺🇦!