が負傷した

was injured

→ が
phrase Rare #20,357
was injured が marks the person or people who were injured. 負傷した is a somewhat formal way to say “was injured” or “got injured.”
JA: 事故で三人の乗客が負傷した。
EN: Three passengers were injured in the accident.

その事故でその電車の乗客数人が負傷した

Several passengers on the train were injured in the accident.

その事故で多くの乗客が負傷した

Many passengers were injured in the accident.

その事故でかなり多くの人たちが負傷した

Quite a lot of people were injured in the accident.

大勢の仲間が負傷した

Many of my comrades were injured.

— カンフーハッスル (2004)

その事故で息子が負傷したという知らせは彼女には大きなショックであった

The news that her son had been injured in the accident came as a great shock to her.

アリョーシャが負傷した

Alyosha has been injured!

— コーカサスの虜 (1996)

大尉が負傷した

The captain was wounded.

— 続・夕陽のガンマン (1966)