(Video) Wisconsin native and Iraq War vet critically injured by police in Occupy Oakland protest

Scott Olsen, 24, who was originally from Wisconsin according to the Guardian newspaper, is currently in critical but stable condition at Highland Hospital in Oakland. The Huffington Post reports that he’s been sedated and is on a respirator.

Observers say that he was hit in the head by a police projectile and fell to the ground. When protesters attempted to help Olsen, police reportedly threw a flash-bang grenade into the group. A graphic video shows an unresponsive Olsen being carried away by protesters.

The Guardian reports that Olsen served in the 3rd Battalion of the Marines. He was a member of anti-war group Veterans for Peace. He currently lives in Daly City, Calif.

Occupy protesters were rousted from a city park early Tuesday, spurring hundreds of supporters to flood the streets. Police from more than a dozen departments responded by making arrests and using chemical crowd control agents like tear gas. There were also numerous protester reports of police using rubber bullets.

Democratic Oakland Mayor Jean Quan responded to the Tuesday morning police actions on Facebook with a statement thanking “police, fire, public works and other employees who worked over the last week to peacefully close the encampment.” Quan cited the city’s desire to “maintain safe or sanitary conditions.” So far, more than 5,700 mostly critical comments have been left on her Facebook post, including many that reference Olsen.