PORTLAND, Ore. -- A man celebrating his 21st birthday Saturday night suffered serious injuries when he was attacked by a group of men in downtown Portland.

Tyler Backman said the beating occurred near Southwest First Avenue and Couch Street. He had just left McFadden's bar to find his friend, who was ill in the back of a car a few blocks away.

Backman said a large group of men -- as many as seven of them -- asked for his wallet and then attacked.

"All I remember is someone punched me in the back of the head," Backman said.

Backman said he yelled for help as he lost consciousness.

"They just kept kicking me and kicking me," he said. "I was just yelling, 'Why?'"

Backman suffered numerous injuries in the beating. He later woke up at a hospital with six broken ribs, a broken sternum, a punctured lung, a bruised lung and a possible spinal injury to his neck.

"I couldn't breathe so I thought was I going to pass out or die," he said.

Backman is unemployed and has no medical insurance. He and his family said they want the attackers captured and punished, but Backman said he also wants to know why the group chose him.

"I don't know. Maybe they were just looking to take some anger out on someone," he said.

Portland police said they're investigating the case and seeking witnesses. They're also considering whether surveillance video may show images of the attackers.

An account has been set up at U.S. Bank in Tyler Backman's name to help with medical expenses.

Man's 21st Birthday Ends In Downtown Beating