When 17-year-old Jaydon Chavez-Silver was shot at a party in Albuquerque last month, one of his friends did what anyone would do under those horrible circumstances: She called 911.

“I’m doing CPR as we speak,” Esperanza Quintero told the dispatcher. “I’m keeping him alive.” However, that 911 call ended abruptly when the dispatcher hung up on Quintero, after the 17-year-old caller cursed at him in a moment of frustration.

“Okay, you know what, ma’am?” the dispatcher said to Quintero as her friend was dying. “You could deal with it yourself. I’m not gonna deal with this, okay?”

That dispatcher, Albuquerque firefighter Matthew Sanchez, resigned Tuesday night, according to the Albuquerque Journal.

Sanchez had been placed on administrative leave before his resignation. The June 26 incident is under investigation, Albuquerque Fire Chief David Downey said in a statement. “As the chief of the department, I am taking the allegation very seriously,” Downey said.

“It was his job,” Quintero told ABC affiliate KOAT. “I don’t understand why he would have hung up.”

[‘I’ll put a hole right through your head,’ Mass. police detective tells driver]

Emergency responders had already been dispatched to the house before Sanchez hung up on Quintero. Chavez-Silver later died at a hospital.

The majority of the 911 call’s audio, released earlier this week, has been redacted, but here’s the relevant exchange between Sanchez and the caller:

QUINTERO, the caller: I’m doing CPR as we speak. I’m keeping him alive.

SANCHEZ, the dispatcher: Okay, is he not breathing?

QUINTERO: Barely. Stay with him. [inaudible] Stay with him, good job. Just stay with me, okay, okay. There you go. Good job Jaydon.

SANCHEZ: Is he breathing?

QUINTERO: He’s barely breathing. How many times do I have to f—— tell you?

SANCHEZ: Okay, you know what ma’am? You could deal with it yourself. I’m not gonna deal with this, okay?

QUINTERO: No, my friend is dying —

Sanchez ended the call mid-sentence.

Sanchez was a 10-year veteran of the fire department, according to NBC News, and had worked as a dispatcher for more than three years.

[Emergency dispatcher to 13-year-old girl as her dad dies: ‘Stop whining’]

“It is heartbreaking to listen to,” Nicole Chavez, Chavez-Silver’s mother, told NBC affiliate KOBF. The family had heard rumors that the 911 dispatcher hung up on Quintero, but had no confirmation until the audio was released to the media.

“Right now, we just want to find the people responsible for this violent, deadly crime,” Chavez added. The family is offering a reward for information.

Police are still searching for the person who shot and killed Chavez-Silver at the party, according to KRQE. It’s believed that the teenager may not have been the intended victim of the gunfire, which was possibly a drive-by shooting. He was pronounced dead upon arrival at a local hospital.

Quintero said Tuesday that her friend may have died regardless of how the 911 call ended. “I don’t know if he would have made it or not,” she told KOAT.

The shooting is “a possible case of being in the wrong place at the wrong time,” Albuquerque Police Sgt. Simon Drobik said at a news conference following the shooting last month, “and some low-life, like I said, shot into the house and [Jaydon Chavez-Silver is] now deceased, in the prime of his life.”

The ABC affiliate added:

She does wish, however, that Sanchez had done more to help her.

“Just a little, ‘Hey I’m here, it’s going to be OK, don’t worry,'” she said. “Something little, instead of ‘What are you doing, what are you doing, what are you doing, where are you at,’ then click.”

Now she has a few things to say to Sanchez.

“I’m sorry. I’m sorry that I gave you attitude or I got upset with you,” she said, adding she does not think that excuses his reaction.

Quintero told the station that she couldn’t understand why Sanchez hung up after she used a single expletive.

“I was frantic; I was scared,” she said.

Sanchez, she said, “should find something else to do because, obviously, helping somebody is not for him.”