Most of us have read about the gorilla escape at Riverbanks Zoo but few know why the gorilla returned to his compound so soon after his escape. Here’s what really happened:

It’s Friday afternoon in mid-June at Riverbanks Zoo. Mike, a 400-pound gorilla, is lounging in his compound contemplating something he hasn’t seen before.

A severe thunderstorm caused several bamboo shoots to buckle and hang down against the inside wall of the gorilla compound. Mike ambles down into the earthen moat and grabs a couple of dangling bamboo shoots. Now the big ape simply walks up the retaining wall hand-over-hand gripping the dangling bamboo. Once atop the retaining wall, the 400-pounder leaps to the sidewalk in a place normally reserved for zoo visitors.

Mike is spotted almost immediately by security guards who quickly set in motion an emergency procedure. Staff and visitors are quickly herded into buildings and doors are locked.

Two people somehow miss the hurried evacuation. They are food service contractors -- a man and a woman. Mike sees the two, ambles over to them and back hands the woman. The smack doesn’t knock her down, but it gets her attention.

Next Mike reaches for the guy who has curled up into the fetal position. The gorilla picks the guy up, but at that moment spots a woman some 30 yards away.

The woman he sees is not just any woman. She’s the zoo keeper for the gorilla compound. The lady in charge!

Who knows what a gorilla thinks at a moment like this? My guess is Mike is thinking: "Uh, oh, there’s my momma. I’m not supposed to be out here. I’m a bad boy. Better get back in my own yard." Instantly, Mike drops the guy and leaps back into the gorilla compound.

Zoo officials, who’ve thought of just about everything to keep a safe environment, trim the bamboo tops around the perimeter of the compound so shoots won’t enable Mike or his playmates, to do any more hand-over-hand scaling of the wall. Kudos to the zoo folks.