Please see Governor Mary Fallin's executive order [2] to have all flags at half-staff through the end of the day tomorrow Oct. 31, 2018, in respect of the victims in Pittsburg, Pennsylvania.
Links:
[1] https://my.metrolibrary.info/drupal/locations/all-locations
[2] https://www.sos.ok.gov/documents/executive/1836.pdf
[3] https://my.metrolibrary.info/drupal/tags/flags