A collision between a sanitation truck and an ambulance in Crown Heights has left three people hospitalized in serious condition.

The crash occurred on Dean Street near Classon Avenue around 10:09 a.m., fire officials said, sending one sanitation worker and two emergency workers to Brookdale Hospital with serious injuries. Though the circumstances surrounding the collision are unclear, one onlooker tells us that the ambulance sirens were on at the time of the crash, and that it did not appear to be carrying any patients.