Two adult male gorillas escaped from their enclosures at the Kansas City Zoo on Sunday, Feb. 19 at approximately 2:15 p.m. The incident occurred because two keepers accidentally left the doors of the interior cages unlocked.

The gorillas, after leaving their cages, entered the hallway of a holding building, and keepers exited into the currently empty outside exhibit, where the employees exited with the use of a ladder.

During the escape, the gorillas did not have access to the public zoo area, but only the outside exhibit. The zoo has three populations of gorillas, the two males that escaped, a single male, and a male and two females. The populations share the outside exhibit, although only one can be allowed in it at one time. It was during a transition period, when the male and females were being brought inside so that the two males could go out, that the escape occurred.

“Obviously, there will be disciplinary action,” zoo director Randy Wisthoff said in an interview with The Kansas City Star.

According to Wisthoff, zoo protocols will be re-evaluated and discussed.