It started out as a sweet family moment on a day trip to the zoo : a little girl beating her chest at a gorilla , safely separated by a pane of glass . But it seems the Silverback at the Nebraska zoo was less amused . The massive animal - who had been standing at the back of the enclosure - clearly decides enough is enough , and runs at the onlookers . Playful : The little girl can be seen in the window beating her chest at one of the gorillas . Cross : But the gorilla 's friend in the background is n't quiet as keen on the game . Sprint : And he decided the time had come to do something about it - so started running towards the glass . Heavy : The gorilla throws his entire weight at the pane of glass at Omaha 's Henry Doorley Zoo . The gorilla then launches himself , and his hundreds of pounds , at the little girl , hitting the glass with such force it cracks . The terrified family have fled to safety in the meantime . The incident took place at Omaha 's Henry Doorley Zoo yesterday , and since it was uploaded to YouTube it has had more than 126,000 views . Writing on Reddit , the person who uploaded the video revealed : 'The person added : 'Shortly before this we were telling the kids they could not break it . They will never believe us again . 'Sadly the one beating her chest really started crying . ' They added : ' I came back a couple of minutes later , and the zoo keepers were telling people to stay away . ' Horror : The family 's terrified reactions were captured in the glass the moment they gorilla hit . Impact : The force is so much the glass cracks on impact - sending the family fleeing . Huge : Mountain gorillas like this one can weigh as muhc as 485lb , or 220kg . Male mountain gorillas , which can reach the age of 40 , weigh between 300 and 485lb ( 220kg ) . They are classified as an endangered species , and Henry Doorley Zoo is famous for its gorilla breeding programme . The zoo was responsible for the first gorilla test tube baby in 1995 , and now boasts the largest gorilla sperm bank in the world .
Toddler filmed beating her chest at the Silverback at a Nebraska zoo . Gorilla then takes a run at the glass - and hits it with such force it cracks . The footage captures the terrified family running for their lives . Video of yesterday 's incident has got 126,000 views since it was uploaded .