The unions for teachers and bus drivers in the Cherry Creek School District went to court Friday in an effort to block the release of disciplinary records sought by 9NEWS as part of a wide-ranging investigation of crashes involving school buses in Colorado.

As part of its examination of more than 1,500 school bus wrecks reported in Colorado since 2011, 9Wants To Know had sought disciplinary records for drivers from 21 districts who were involved in crashes that were deemed by police to be their fault and that resulted in injuries.

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The Cherry Creek School District was one of four that refused to release those records.

After attorney Steve Zansberg appealed on behalf of 9NEWS, district administrators relented this week and decided to release the records. However, the Cherry Creek Transportation Employees Association, which represents bus drivers, and the Cherry Creek Education Association, which represents teachers, sued the district to block the release.

Tustin Amole, spokeswoman for the district, was also named as a defendant because she is the official custodian of records for Cherry Creek schools.

Amole said neither she nor anyone else from the district could comment Friday.

The unions contend that the records in question are barred from release by a section of state law that deems “personnel files” closed to the public. The employees in question “have legitimate expectations of privacy in their personnel records,” attorney Sharyn E. Dreyer wrote in the complaint.

Zansberg argued, however, that multiple court rulings make it clear that disciplinary records are not subjected to the personnel files exception in the Colorado Open Records Act and therefore must be released.

The 9Wants To Know investigation was carried out after two frightening school bus crashes in late 2015 – one outside Durango, the other outside Lyons – that both resulted in multiple injuries. In the Durango crash, investigators concluded that the driver was distracted as he reached for a whistle to quiet rowdy students. In the Lyons wreck, prosecutors have alleged the bus driver was under the influence of multiple prescription drugs.

Both buses went off the road and rolled over.

The 9Wants To Know investigation found that more than 700 of the crashes reported since Jan. 1, 2011, were the fault of the bus drivers. Part of that investigation zeroed in on roughly 70 crashes where the driver was at fault and injuries were reported.

As part of that, 9NEWS requested records of complaints about the performance of those drivers and about discipline meted out by the districts.

Those records were provided by a dozen of the districts: Adams 12, Aurora, Boulder Valley, Douglas County, Durango 9-R, Falcon 49, Fountain-Fort Carson, Jeffco, Lewis-Palmer, Poudre, St. Vrain Valley and Thompson. Three other districts had no records of complaints or discipline, and the 9NEWS requests to two other districts have not been resolved.

Only Cherry Creek School District, Denver Public Schools, Swink School District, and Westminster Public Schools refused to release the records, arguing they were personnel files that are not open to the public.

The request from 9Wants To Know for Cherry Creek records was originally filed Jan. 22. On Feb. 5, Cherry Creek officials denied the request.

On March 14, Zansberg filed the appeal on behalf of 9NEWS as part of the services he and his law firm provide to the Colorado Freedom of Information Council.

According to the suit, Cherry Creek School District administrators decided this week to release the records and notified representatives of the two unions. The unions objected, according to the suit, and threatened to sue. An attorney for the district told lawyers for the unions that if the suit was not filed by the end of the day Friday it would release the records.

Contact 9NEWS reporter Kevin Vaughan with tips about this or any story: kevin.vaughan@9news.com or 303-871-1862.