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.

The man charged with fatally mowing down an FDNY EMT two years ago — after swiping her ambulance and taking it for a stoned joyride — was finally declared fit for trial on Thursday.

“It seems like the wheels of justice are moving in the right direction,” said Ali Acevedo-Hernandez, aunt of Yadira Arroyo, the EMT who was killed.

FDNY EMS members filled the courtroom on Thursday during the hearing for Jose Gonzalez, who is accused of running over Arroyo — a mother of five — in March 2017. The career criminal was initially declared unfit last year by state shrinks following a series of psychological tests, but prosecutors later contested those findings and requested a hearing.

On Thursday, Bronx Judge Michael Gross described how the court received “a total of five separate reports from psychiatric examiners” — with the three most recent all concluding that Gonzalez was “not an incapacitated person.”

“I asked the court to accept the findings and the criminal proceeding will go forward,” said Assistant District Attorney George Suminiski.

“We are in no way contesting the findings of the doctors,” replied Gonzalez’ court-appointed lawyer, Alice Fontier.