UVALDE, Texas -- In the first hours and days after the massacre at an elementary school in Uvalde, Texas, officials said they figured out how the gunman got into a building that was supposed to be secure.
"The exterior door," the top police official in Texas told reporters, "was propped open by a teacher."
That statement by Col. Steven McCraw, director of the Texas Department of Public Safety, would be quietly retracted within a few days. Instead, DPS officials said later, the door had been shut by the "teacher" but, for some reason, it didn't lock even though it was supposed to do that automatically.
TIMELINE: Tracking the changing story of the Uvalde school shooting
For the school staffer McCraw was referring to -- the very woman who called 911 to report the gunman was on the way to entering Robb Elementary School -- the blame and the events of May 24 still reverberate in a life forever scarred.
Speaking publicly for the first time to ABC News, Emilia "Amy" Marin, a school aide who worked with students after school, said she still struggles through post-traumatic stress from the shooting and its aftermath. She insists that the world know what happened -- and what didn't -- on a warm sunny morning that would turn unspeakably ugly in South Texas.
"I died that day," Marin said in an interview with ABC News correspondent John Quiñones.
"Right now, I'm lost. Sometimes I go into a dark place. And it's hard when I'm there, but I tell myself, 'you can't let him win. You can't let him win,'" she said, referring to the gunman. "I'm a fighter. I will be okay. I'm going to learn to live with this."
By now, the casualty count from the Uvalde massacre is well known: 19 students and two of their teachers were killed when an 18-year-old shooter, a former student at the school, attacked in the final days before summer vacation. What sent him to that school on that mission remains under investigation. McCraw is due to update the progress of the probe when he testifies later this week in Austin.
In the months since the rampage, official information from authorities has been limited and much of the focus has fallen on the botched response by police who did not attempt to stop the shooting for more than an hour. For Marin, who said she still cannot work and continues to replay the minutes of May 24 in her head, the struggle now defines her life.
"I am suffering mentally, of course, emotionally," she said. "I am suffering from post-traumatic arthritis, which is very painful. There are nights when everybody goes to bed and I just stay awake with the pain and my daughter tells me ... 'Mom, soak in the tub.' And I tell her I can't because I can't get out."
"I sit there at night, replaying that day in my mind," Marin said as she explained the events of a day that saw one of the worst school shootings in American history.
"And I see those victims' faces. I pray for them every night," she said. "But what I go through, McCraw doesn't know. Nobody knows. But it was very easy for him to point the finger at me. A few weeks ago, I told my counselor 'It would have been better if he would have shot me, too.' because the pain is unbearable. And when you have people who are higher up in ranks like McCraw, you would think that they know their job well. He has no idea what his words did."
"I will never be the person that I was before," she said. "I did die that day. I see the windows boarded up and the fence around the campus. I tell my counselor, 'I'm in there. I'm still in there.'"
In a statement to ABC News, DPS spokesman Travis Considine explained: "At the outset of the investigation, DPS reported that an unnamed teacher at Robb Elementary School used a rock to prop open the door that the shooter used to enter the school building. It was later determined that the same teacher removed the rock from the doorway prior to the arrival of the shooter, and closed the door, unaware that the door was unlocked. "
Considine said "DPS corrected this error in public announcements and testimony and apologizes to the teacher and her family for the additional grief this has caused to an already horrific situation."
Marin worked as a speech pathologist in the special education program at Robb Elementary and coordinated after-school programs, and said she always wanted to work with children.
"I have always loved children and I always wanted to be around them," she said. "It doesn't matter if you are having a bad day, they will always make it better."
A native of San Angelo, Texas, about 200 miles north of Uvalde, Marin said she wants the country to know what she did that day, when confronted with the worst-case scenario: a man with a rifle and untold rounds of ammunition heading straight for the door of the elementary school where she worked. This was the first time she detailed those events to anyone outside of her family or law enforcement.
As she prepared for an end-of-school party that morning, Marin heard the crash of a gray Ford pickup outside and called 911, thinking someone was hurt.
"I walked out and then they yelled he had a gun, I ran back in. I ran back to the building and I closed the door," she said. "I am telling the operator that he is shooting. I could hear the kids screaming."
Marin said that children were outside on the playground, running for their lives.
"I could hear the kids screaming. I closed the door. I went in and knocked on the teacher's door across from me. I was banging," she continued. "She opened it. She said 'What is going on?' I said there is a shooter on campus."
Still on the phone with emergency operators, Marin decided to hide as she heard gunshots firing off.
"There was shooting and it wouldn't stop. He just kept shooting and shooting," she said. "I looked around and I hid under the counter. The whole time I am asking the operator, 'Where are the cops? Where are the cops?'"
But the almost 400 law enforcement officers who would arrive on the scene did not rush in to the classroom where the killer was still confined with his victims until over an hour later. That slow response has led to a wide chorus of criticism for the police and federal agents who responded to Robb that day. The school district's police chief has been fired, as has one of the first Texas state troopers to arrive. A second trooper who left DPS to go to work for the Uvalde school system has since been terminated by the district. And the superintendent of schools stunned the grieving community this month when he announced his retirement.
Marin said she wonders if her own death in those first few moments could have saved children.
"Every day they tell me, 'You were there for a reason. God put you there for a reason.' I want to know why," she said. "If I had gone out a few seconds later I would've met him outside. He would have shot me. With him shooting me, would I have saved all of them? Would I have given those teachers time to save themselves and the kids?"
She says in the days after the shooting, disbelief took hold of many of the staff who survived.
"It was like did it really happen? We always say it is not going to happen here. It is not going to happen in our town," she said. "Like in Sandy Hook, you see this story and it happened. It can happen anywhere."
When Marin heard McCraw blame her personally for the shooter's ability to gain access to the school, she said she became so distraught that her daughter had to take her to the hospital.
"I was shaking from head to toe," she said. "The nurse walked out and my boss came in and I told her I closed that door.'"
After the shooting, Marin said she asked to speak with Uvalde schools Superintendent Hal Harrell. She said she was told Harrell would not come see her in the hospital and she would ultimately never speak to Marin again.
"Administration let us down. They failed us. He could have defended me. He knew who 'the teacher' was and chose not to," Marin said. "It makes no sense when you have dedicated your life to working for the district."
"I wish he would've handled this differently. It doesn't cost anything to check up on your employees," she said. "I have not heard from any administration since the incident."
Harrell this month announced he would be stepping down next week. His spokeswoman has not responded to a request for comment.
Precisely five months since the day of the shooting, Marin said she's prepared to fight for herself.
"Maybe a lot of people didn't know that it was me," she said. "But they're going to know now and I've always been the type. Like, I'll be respectful, but I'll speak up. And people don't like it when you speak up. But you're defending yourself. And I know that I have to defend myself."
Marin has filed suit against the manufacturer of the gun used in the Robb shooting and she is considering other legal options.
She said she is also dismayed at the fractures that have developed in her town.
"We are supposed to as a community to be united and work through this and help these families, help everyone involved," she said. "They say we are 'Uvalde Strong.' We are not. We are divided. How can we divide over 19 lives lost? It doesn't make sense."
As for McCraw, who pinned the blame for the massacre on her, Marin said she has one message.
"To Mr. McCraw: it is your job to investigate when any incident like that happens. You sit there and you investigate. Your job was to sit there and watch that video to watch from beginning to end. You chose not to."
Uvalde:365 is a continuing ABC News series reported from Uvalde and focused on the Texas community and how it forges on in the shadow of tragedy.