The 1999 Moscow apartment bombings across Buinaksk, Moscow, and Volgodonsk[1].
The engine reads them as a crisis used to consolidate power.
Over 300 people were killed and the attacks were blamed on Chechens; in the Ryazan incident, FSB agents were caught by local police planting the explosive hexogen; the crisis lifted Putin's approval from 2% to a national majority and provided the pretext for the Second Chechen War.
It's presented as a case of a security crisis being used to vault a leader into power, which the engine treats as structurally parallel to other leaders' security crises.