This is the 4872nd most frequent Korean word.
교통사고로
"Due to a traffic accident"
Here, '교통사고로' indicates the cause or reason for the following action, namely being hospitalized.
그는 교통사고로 병원에 입원했다.
He was hospitalized due to a car accident.
In this sentence, '교통사고로' is used to specify the reason for the missed appointment.
나는 교통사고로 인해 중요한 약속을 놓쳤다.
I missed an important appointment because of a car accident.
In this example, '교통사고로' is again specifying the cause of suffering.