MILWAUKEE (CBS 58) -- A Milwaukee mother is suing three years after a tragic accident at Barack Obama High School.

Trenton White, 17, died after he did a backflip and landed on his neck, leaving him with spinal and brain injuries.

The lawsuit says the school gym teacher and principal failed to supervise the students.

White's mother is also suing the school board for negligent hiring, training, and supervision of school staff.