On the day a six-year-old pupil shot and wounded his teacher in the US state of Virginia, school leaders were warned three times that the boy might have a gun, a lawyer for the teacher said.
This included a request to search the boy and a report from another child who said the boy had shown him a gun.
The teacher - Abigail Zwerner, 25 - is recovering after being released from hospital last week.
In the fallout, the school's superintendent has now lost his job.
Board members of Richneck Elementary School voted five-to-one to sack George Parker.
The removal of Mr Parker happened only hours after Ms Zwerner's lawyer, Diane Toscano, announced plans to sue the district, saying the shooting was "entirely preventable".
Police have not announced any charges.
The 6 January shooting - which authorities have described as "intentional" - rocked the Virginia city of Newport News, and raised questions about what legal consequences may follow and for whom.
"On that day, over the course of a few hours, three different times - three times - school administration was warned by concerned teachers and employees that the boy had a gun on him at school and was threatening people," said Ms Toscano.
"But the administration could not be bothered."
According to Ms Toscano:
- Around 12:30 a teacher reported she had searched the young boy's backpack believing he may have a gun. She did not find one, but told an official the boy may have put the gun in his pocket before going out for break. The official allegedly responded: "Well, he has little pockets."
- Around 13:00 another teacher reported the boy had shown a child the gun and threatened to shoot him if he told
- A different employee asked to search the boy and his backpack, but was told to wait because the school day was almost over
At around 14:00 the boy pointed the gun at Ms Zwerner and fired in the middle of a lesson, police said.
Newport News police chief Steve Drew has said Ms Zwerner saved lives by ushering her students out of the class after being shot through the hand and in the chest.
Newport News Mayor Phillip Jones thanked the outgoing superintendent, and said he supports the board's effort to "hire a dynamic, new leader for our public school system - one that will help us heal and move forward with the necessary changes to make our schools safer for everyone".
The superintendent's salary was over $250,000 (£200,000) per year, according to local news outlets. He will continue to receive full salary and benefits until June 2024 because he was fired "without cause".
As well as the departure of the superintendent, the assistant principal of Richneck Elementary School is also leaving his post after resigning.
Ms Toscano's claims are bolstered by text messages exchanged between the school's teachers and obtained by the Washington Post. According to the messages, Ms Zwerner had raised concerns about the six-year-old and asked for help.
Last week, the family of the young boy said he suffered from an "acute disability" and rarely attended school without one of his parents being present. The day of the shooting he had attended school alone.
The family also praised Ms Zwerner, saying she had "worked diligently and compassionately to support our family as we sought the best education and learning environment for our son".
Police said the gun used by the boy had been legally purchased by his mother. The boy's family said the weapon had been "secured". Police have not responded to this claim.
Virginia law prohibits anyone from recklessly leaving a loaded, unsecured firearm in such a way that may endanger a child under 14 years of age.