(CNN) -- Two men, shocked at what they saw, describe an unarmed teenager with his hands up in the air as he's gunned down by a police officer. They were contractors doing construction work in Ferguson, Missouri, on the day Michael Brown was killed. And the men, who asked not to be identified after CNN contacted them, said they were about 50 feet away from Officer Darren Wilson when he opened fire. An exclusive cell phone video captures their reactions during the moments just after the shooting. Intense clashes during Ferguson protest Protests disrupt Ferguson town meeting "He had his f**n hands up," one of the men says in the video.