“I watch my daughter die”

A man accused of charging and plowing his pickup truck into a group of Lower East Side residents celebrating the Fourth of July last year faced harrowing testimony from those reeling from the carnage as his quadruple murder trial began Monday in Manhattan.

Daniel Hyden, 44, sat silently as friends and relatives of the four people killed after allegedly running a stop sign, riding a curb and launching his Ford F-150 through a fence in Corlears Hook Park last summer took the stand against him in Manhattan Supreme Court.

Distraught Liliana Ruiz, 51, broke down in tears as she told the court she rushed to her 30-year-old daughter’s aid and saw the life drain from her eyes as she lay pinned under Hyden’s truck.

“I’m smacking her face,” Ruiz testified, struggling to speak as she described her efforts to keep her daughter awake, saying her eyes looked like “saucers” and her lips slowly turned purple.

“‘Emily, everything will be fine. … Don’t close your eyes,'” Ruiz said. “I was just thinking, I’m watching my daughter die right now.”

After doctors arrived, the grieving mother said she went to gather her belongings to take to the hospital after Emily Ruiz’s panicked grandson suggested she bring a first aid kit.

“He tells me, ‘I don’t want my mother to die. She’s a great person,'” Ruiz, his grandson, quoted tearful tears.

The elder Ruiz said she faced any mother’s worst nightmare when doctors declared her daughter brain dead at Bellevue Hospital.

“What choice did you make? “” Assistant District Attorney Matthew Bogdanos asked Ruiz.

“Let her go,” Luiz said, sounding inconsolable.

Hernan Pinkney, 38, his mother, Lucille Pinkney, 59, and Ana Morel, 43, were killed in the crash with Ruiz. Seven other people, including children, were injured, according to prosecutors.

Hyden has pleaded not guilty to four counts of second-degree murder, aggravated vehicular homicide and related charges and could spend the rest of his life in prison if convicted.

He is accused of entering the park near the Vladeck Houses with a blood alcohol level more than twice the legal limit, less than an hour after being escorted off nearby Pier 36 after the crew aboard the Boss Lady NYC said he was too drunk to sail, as previously reported by the Daily News.

In court Monday, the man’s attorney, Theodore Herlich, argued that Hyden did not brake suddenly because he had injured his foot earlier in the evening, not because he was drunk.

In his opening statement, Bogdanos cited an excerpt from Hyden’s book, written after he supposedly battled his addictions and implausibly titled “The Sober Addict: A Guide to How to Be Functional with the Dysfunctional Disease of Addiction.”

“’A real danger to others, my bike and myself when I was on the road drunk,’” the prosecutor read from the book, saying Hyden was clearly aware of the risks of driving drunk and did so consciously anyway.

State Supreme Court Justice April Newbauer, who presided over the trial, also heard Monday from Hector Moreno, Hernan Pinkney’s childhood best friend, who was present at the Independence Day celebration.

Moreno identified several of those killed laughing and dancing happily in cellphone footage taken at the barbecue hours before the incident. Testifying that he was still in severe pain after a herniated disc dislocated in the crash, Moreno said he did not see Hyden arriving, but heard him revving his engine.

Moments after the massacre, Moreno said, he rushed to the driver’s window, finding a disoriented-looking Hyden with his foot on the accelerator, shirtless and without a seat belt and trying to move the gear lever — while several victims remained trapped under his vehicle.

“I just started hitting him as hard as I could,” Moreno testified.

When asked to identify the driver, Moreno looked at Hyden in court and pointed his finger directly at him, telling Newbauer he had no doubt.

The trial continues Tuesday.