An Ofsted inspection report published today has given the school an Inadequate rating, saying when inspectors visited discrimination was common and physical violence among some pupils was "a regular occurrence".
It also said "sexual harassment is distressingly common. Some staff described this as a ‘culture’ in the school.
"Many pupils regularly experience inappropriate comments. There have been a number of instances of inappropriate touching and assault," said the report.
"Some pupils also experience shocking threats of sexual violence.
"Leaders are not doing enough to protect pupils from these experiences or reduce the risk to pupils."
Brooksbank has seven local primary schools as "feeder schools" - All Saints Primary, Bowling Green Primary, Cross Lane Primary, Elland C o fE J and I, Holywell Green Primary, Old Earth Primary, St Patrick’s Catholic Primary, The Greetland Academy and West Vale Primary schools.
The school says action has been taken since the inspection in February, and insists it is now a safe and welcoming place for pupils and staff.
It says changes have been implemented which have transformed how it supports students.
The Ofsted report said: "A number of pupils told inspectors they were afraid of being ‘jumped’ in school. There are many areas of the school where pupils don’t feel safe.
"Some staff who supervise pupils do not challenge poor behaviour. Many pupils do not trust staff to protect them from dangerous situations.
"This poor behaviour affects pupils in all year groups, including those in the Sixth Form."
It added that new leaders had begun to take action to improve behaviour in lessons and this had reduced low-level disruption in classrooms so that, in more
lessons, pupils were able to concentrate on their learning.
But it said: "These steps have not been sufficient to make the school a safe place for pupils.
"The school has not created a culture where all pupils are respected and treated equally by their peers. Pupils are discriminated against because of their race and religion. Pupils frequently hear racist language. Leaders have done little to address this.
"Pupils are also targeted because of their sexual orientation. Pupils hear discriminatory language, such as homophobic language, every day.
"Discrimination by gender is also common. Some pupils judge others on how they look. Leaders have taken some steps to address these issues, but this has not gone far or fast enough.
The report also said: "The teaching given to prepare pupils for life in modern Britain is lacking. It does not ensure that pupils know how to relate to others or how to be safe and active citizens in later life.
A spokesperson for The Brooksbank School said: "The Brooksbank School is now a safe and welcoming place for students and staff.
"Immediately after the inspectors shared their findings in February, we took swift action to secure immediate and rapid school Improvement via the Education Exchange, which has provided senior leadership expertise, capacity, training and support.
"Senior leaders have led the implementation of changes that have transformed how we support students.
"We have systems and structures to ensure any negative behaviour is dealt with effectively. The new systems and policies support high standards and all staff have had training to deliver these changes.
"Splitting the lunch and break times has changed the feel of the school and allowed supervision to ensure that all students feel safe during social times. The update of our reporting systems means you can be confident we are monitoring and acting on issues raised with us.
"We are pleased inspectors recognised the expertise of our teachers, the ambitious curriculum in the Sixth Form and the wide range of opportunities and careers guidance offered to pupils.
"Working with the Education Exchange has allowed us to benefit from the knowledge and expertise of school leaders from across Yorkshire and The Humber.
"Students and staff relished the opportunity to participate in the recent GCSE masterclasses in English, Maths and Science, just one of the initiatives for our school which flowed from this project.
"Alongside our academic work, we have established a series of curriculum activities and changes to promote inclusions and respect. This approach has been received well by students and staff and already we can see the impact of the pastoral programme now in place.
"We would like to acknowledge the support from our school community and local partners. We are working together with others to ensure that the changes we have already made are securely embedded and that the school can move forward confidently."