Nine-year-old Kaidyn Green was hit by a driver last December outside KIPP DC school. He died this June after complications from the crash, which left him in a wheelchair, and now his family has filed a wrongful death lawsuit against the school, the security company that protects the school, and the driver and owner of the vehicle that hit him.

The lawsuit, filed this week in Superior Court of D.C., says the school and security company, LGC Security, didn’t do enough to keep Green safe.

The lawsuit says Green was left unattended and unsupervised in the halls and outside the school before he was hit. He was supposed to meet his mom, who was told to wait in the office for her son. The usual process involves a parent signing in and then the child being brought to the office by a teacher, security guard, or another employee. A school employee told him to go to the office but did not escort him.

Instead, Green was unsupervised in the halls and a stairwell, left through an exit, and went outside. He saw his mom’s car across the street, looked both ways, but was hit crossing the street. He landed 20 feet from where he was hit, the lawsuit states. It also says the school and the District Department of Transportation knew Wheeler Road SE was dangerous, with multiple fatal pedestrian crashes there in the years and months before Green was hit.

The lawsuit says the school is responsible for the care, safety, and welfare of students at the school and they are to be monitored at all times.

The family is seeking more than $50 million.

Their attorney, Keith Watters, says they also want to make sure another incident doesn’t happen like this at schools.

Green was hospitalized at Children’s National for two months and became a quadriplegic because of the crash. He was given at-home care, but Green died June 2 after a ventilator tube was left disconnected by a nurse.

In a statement, KIPP DC wrote, “Our community continues to mourn Kaidyn’s passing and our thoughts are with his family and the classmates that knew him so well. Given the pending legal matter, we’re unable to say more at this time.”

The security company wrote,” “LGC Security is deeply saddened and shaken by the tragic incident involving Kaidyn Green at Kipp DC. Our hearts are with the family. There is no higher priority than the safety of students and patrons at the schools, events, and facilities we have the privilege of serving. We are not able to comment further at this time due to active litigation, however, we take this matter very seriously and additional details will be provided via the legal process.”

WAMU was not able to find contact information for the driver or vehicle owner but will update this story if they have comments.