Two teens' robbery attempt failed when a security guard chased them down outside a popular burger spot.

The robbery happened late Saturday night outside Chris Madrid's restaurant in the 1900 block of Blanco.

Police say the teen robbers confronted a man, flashed a knife and robbed him of less than five dollars.

But a security guard alerted to the robbery chased down and caught the teenage thieves.

Police say the kids will be charged with aggravated robbery.