The EMT who watched a maniac run over and kill her partner was left so distraught over the ordeal that she resigned from the department, The Post has learned.

“The passing of my partner Yadira has changed my life forever,” Monique Williams said of the March 2017 caught-on-camera ordeal. “I will never forget that tragic day. That incident has caused me great pain. I am no longer with the FDNY due to this traumatic experience.

“I will never forget Yadira Arroyo.”

Williams could be heard wailing, “How could you do that to my f–king partner?” in the background in the moments after schizophrenic Jose Gonzalez hijacked their ambulance and mowed down the 44-year-old mom of five on a Bronx street in broad daylight.

Family said the two became close friends while working side-by-side at EMT Station 26 in Morrisania in the Bronx.

Williams, who was 31 at the time of the attack, was photographed sobbing at Arroyo’s funeral — where she was scheduled to read a scripture passage, but was unable to speak when she got to the pulpit.

Williams retired on a disability pension.

Her partner’s suspected killer, Gonzalez, then 25, is charged with murder in the case.