было убито

were killed

→ быть
phrase Rare #44,364
were killed Used in a passive construction; the Russian form stays the same even when the thing or people killed are plural.
RU: В аварии было убито несколько животных.
EN: Several animals were killed in the accident.

Сколько людей было убито в магазине?

How many people were killed in the store?

Было убито ещё трое заложников.

Three more hostages were killed.

На войне было убито много людей.

Many people were killed in the war.

Сколько человек было убито?

How many people were killed?

На острове было убито несколько овец.

Several sheep were killed on the island.

— Дом странных детей Мисс Перегрин (2016)