FORT GREENE — A suspect who became sick in police custody in a Brooklyn station house died after waiting four hours for an ambulance, DNAinfo New York has learned.

Angel Cordero, 39, was being held in the 88th Precinct after he was arrested at roughly 4 a.m. on the Fourth of July and accused of attacking his 48-year-old girlfriend with a knife at the corner of Myrtle and Carlton avenues.

Cops brought Cordero to the station house and put him in a holding cell, but before he was even processed he began to exhibit signs of distress, sources said. Cops called for an ambulance, and one from a private local service responded and brought Cordero to nearby Woodhull Hospital.

During the next hour, Cordero was treated for an undisclosed ailment, and then driven back to the station house by cops and returned to the holding cell, where he remained until the following morning.

At 1:40 a.m. on July 5, Cordero began to show signs of distress again — and the cops this time made their initial call to the FDNY/EMS for an ambulance to tend to “a sick patient.”

EMS dispatchers told the cops that there were no ambulances available because they were tied up dealing with post-Fourth of July incidents around the borough, according to sources.

“There was a scarcity of ambulances that morning,” one source said, “and they were tied up all over on Fourth of July related calls.”

The source said cops at the 88th Precinct did not believe that Cordero’s condition required emergency care — the officers said it was “non-critical.”

They decided to monitor Cordero as they waited for paramedics to become available, sources said.

At roughly 3 a.m., however, the cops at the 88th Precinct called again for an ambulance, sources said. They were again told there were no available paramedics.

At 5:27 a.m., Cordero started to have a massive seizure in the holding cell, according to a police report.

This time the cops radioed and called 911 reporting they now had a full-blown medical emergency on their hands.

But by the time paramedics were dispatched, Cordero had died in the cell, sources said.

The snafu raises serious questions about why the EMS never sent an ambulance during the four-hour ordeal and why the cops failed to drive Cordero back to the hospital themselves instead of waiting interminably for paramedics.

Police commissioner Ray Kelly commented on Cordero's death at an unrelated press conference.

''The only thing I can tell you is any death in police custody is intensely investigated by the Internal Affairs Bureau. That's what's going on now," he said.

FDNY/EMS sources said an average Thursday overnight tour is usually quiet, with a small number of ambulances at the ready. But because this was the night of July 4, the EMS put 15 additional ambulances on the roads in anticipation of heavier volume, particularly in Brooklyn.

Sources said the volume of calls that night was even higher than anticipated.

An FDNY/EMS spokesman said units that morning were relocated to high volume areas and handling cases based on the severity of the incident.

The NYPD call regarding Cordero said they had "a sick person" in the precinct and "we responded accordingly, based on protocols, availability of units and priority," the spokesman said.

The NYPD did not immediately respond to an email seeking comment.

But a veteran police official said cops have to follow strict procedures regarding prisoners and that taking initiative to bring the prisoner directly to the hospital may seem like common sense, but the move would likely get them in trouble.

Woodhull Hospital officials were not immediately available to discuss Cordero's case, but medical care is generally confidential.

The city’s Office of the Chief Medical Examiner has yet to determine Cordero’s cause of death and is awaiting toxicological test results, a spokesperson said.

Trevor Kapp and Gustavo Solis contributed reporting.