The shooter has fled the scene and the police are now searching for the suspect. The authorities urge citizens to avoid the area.
Local KIRO 7 news agency also report 7 people injured and one killed as a result of the shooting.
Three victims are in stable condition, a nine-year-old boy is in serious condition and a 55-year-old woman is in critical condition, according to Fox News. Those injured were reportedly taken to the local Harborview Medical Center.
"This is not an active shooting at this point, but we are collecting evidence and information", Seattle Police Chief Carmen Best said, according to NBC News.
The local Bureau of Alcohol, Tobacco, Firearms, and Explosives (ATF) said on Twitter it was assisting the police in the operation.
Videos from the scene have been shared on social media showing paramedics and police working on the ground.
"I've never experienced anything like this in my life", a nurse who witnessed the shooting said, according to NBC News.
There has been no further information so far concerning the motives behind the incident.