Witnesses at the camp, located in the 700 block of South Main Street, say two men were arguing at about 4:30 a.m. when both men briefly left the area. Police say the victim returned to the camp a few minutes later covered in blood.
Nobody called police or sought medical help for the victim until at 8:30 a.m., and by the time officers arrived they said the man was "struggling to maintain consciousness."
The victim was treated by Seattle Fire Department medics and taken to Harborview Medical Center, where he is being treated for life threatening injuries, according to police.
The attacker is described as a 25-year-old black man with a short Afro who was wearing all black clothing. Officers searched the area but didn't find anyone matching the description.
Anyone with information about the stabbing is asked to call 911.