YOU SAID:

There was an ambulance going to the hospital

INTO JAPANESE

救急車が病院に向かっていた

BACK INTO ENGLISH

an ambulance was heading to the hospital

INTO JAPANESE

救急車が病院へ向かっていた

BACK INTO ENGLISH

An ambulance was on its way to the hospital.

INTO JAPANESE

救急車が病院へ向かっていた。

BACK INTO ENGLISH

An ambulance was on its way to the hospital.