The bodies were discovered around midnight at the Bradford Townhomes near E. 23rd Street and S. 109th E. Avenue.
The victims are two adults, a man and a woman, and two children. No names or ages have been made public at this time.
Tulsa police do believe all four victims were shot.
There was one survivor inside the apartment when the victims were discovered. Police say the survivor is less than 2-years old and was not harmed.
Police have no witnesses and no suspects at this time. They're also working on a motive for the shootings.
News 9's sister station in Tulsa, KOTV-6, is at the crime scene and will be providing live updates all morning on News 9 This Morning and News9.com.