Restoration.

This is coolbert:

Gone for good? Azovstal steelwork an immense industrial complex existing ABOVE and BELOW ground never to be rebuilt!

"Russia explains why it will not rebuild Azovstal steelworks in captured Mariupol"

From news.yahoo.com | Ukrainska Pravda | January 24, 2023. 

"The Russian occupiers do not plan to rebuild the Azovstal steelworks, destroyed in the battle for Mariupol, as it is 'impossible and unprofitable'."

Steelwork Azovstal built post-war World Two on top of a deep underground six-story deep network of bunkers and tunnels. Nuclear-proof they say. Construction of the above-ground steelwork commencing ONLY after the nuclear-proof below-ground facility complete. Click on image to see an enlarged view. 

"Source: Yuliya Maksimova, Head of Roskapstroy Russian Federal Autonomous Institution [company engaged in construction and rebuilding of capital construction projects – ed.], during a press conference for Kremlin-aligned news outlet TASS on 24 January"

"Quote from Maksimova: 'No one is going to rebuild Azovstal, because it is impossible and unprofitable on the scale of that Soviet facility it used to be before...'"

"Such facilities were appropriate and profitable [in the USSR – ed.], they worked and were always busy. Now I think that oblast’s economy will be revised."

I might well imagine that siege of the steelwork with the massive Russian bombardment resulted in a lot of unexploded ordnance [UXB] buried under debris and placing anyone involved in reconstruction of Azovstal in grave danger.

coolbert.