Caught on camera: The moment a two-ton elephant charged and nearly killed his terrified keeper

This is the terrifying moment an elephant charged its keeper.

Security video shows the trainer, Don Redfox, desperately trying to protect himself as Louie the elephant - who weighs two tons - pinned him in a corner, his tusks narrowly missing the man's head and chest.

The elephant then backs away as Mr Redfox stumbles out.

He has been hospitalised with life-threatening injuries since the attack three weeks ago at an Ohio zoo. 

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Deadly: A CCTV image shows Louie the elephant charging his trainer, Don Redfox, who is already injured on the ground. Mr Redfox barely escaped with his life

Doctors have upgraded his condition and expect him to recover from two punctured lungs and several fractured ribs.

Anne Baker, the zoo's director, said it's not clear why Louie turned on the keeper. 

The elephant and Mr Redfox had been together nearly every day since the animal's birth seven years ago.

It looks as if Louie was startled and then started play-fighting, as elephants do in the wild, Ms Baker said.

Mr Redfox makes it a habit to talk to the animals before he approaches so he doesn't surprise them, Ms Baker said. 

She thinks he didn't do it this time because he didn't know Louie was around the corner when he walked into the enclosure carrying a bag of carrots.

'Neither expected the other to be there,' Ms Baker said.

Escape: A wounded Mr Redfox stumbles towards safety as Louie suddenly backs off

They both backed away. Louie flared his ears and moved towards the keeper, pushing Mr Redfox before the keeper stepped safely behind a gate and closed it.

But then Mr Redfox returned and tried to move the elephant away with a pole with a hook on the end. That's when the elephant charged, pinning him in the corner and knocking him to his knees.

Louie backed up, dropped to his knees, and then charged again at Mr Redfox, who curled up and tried to shield himself. 

After that, the elephant backed away again and Mr Redfox stumbled to safety.

Ms Baker said the elephant could have killed Redfox at any time.

Since he did not, she and another elephant expert who reviewed the video think that Louie was play-fighting.

'The problem is Louie weighs over 4,000 pounds,' she said - about two tons.

Zoo officials have not been able to talk with Mr Redfox, who faces a long recovery, according to his doctors.

Mr Redfox and his family initially fought the video's release - but as the incident made its way into the media, they changed their minds, wanting to show that the animal wasn't mistreated.

The family said it continues to believe that 'releasing the security tape does nothing more than provide an opportunity to sensationalise a tragic accident'.

See the video here