The initial Reuters report lists Russian time zone (so early morning December 26th) and mentioned President Vladimir Putin, speaking in St Petersburg, declared Dec. 26 as national day of mourning.
In an effort to try and list all their names, according to Wikipedia...
Choreographer: L. Kulikov*
Administrator: VG Kadin+
Choreographer and coach: V. Ermolin+
Head Dresser: A. Kormilitsyn (Honoured Worker of Culture)
Soloists: VI Shtefutsa and EM Labkovsky; with SV Ivanov, PD Bogachev, VP Maystruk, AA Gvozdetsky, BM Mizyuk (all Honoured Artist of Russia)
Choir: YA Lysenko, Y. Shtrunov, IM Pirogov, IS Sobolev, И.Ф. Volkov, OV Filimonov, AN Savitsky, VA Nagorny, VP Kokarev, AA Hristachev, JN Deynekin, VM Bolonenko, VN Antonov, AN Stritenko, AA Toschev (all Honoured Artist of Russia); and VS Buzlov, SP Lapik, VF Orthodox, GU Razgasimov, V. Chekin, MD Mochalina.
Orchestra: AA Mogulkin, Y. Savkin, MG Chervov, PD Shchennikov, NI Diakov, AI Egorov, VM Predelin (all Honoured Artist of Russia)
Vocal coaches: People's Artist of Russia
Laureate of competitions: MI Glinka and PI Tchaikovsky, Professor KP Lisovsky
Concertmaster: V. Brodsky+
Ballet: GD Pavlyuchenko, IV Konygina, P.U. Khmelnitski (all Honoured Artist of Russia)
* People's Artist of Russia + Honoured Artist of Russia