Police said robbery was likely the motive behind a shooting at a marijuana grow house in SeaTac that killed one man and critically injured another.

King County Sheriff's Office deputies said a woman called 911 just after 2 a.m. Monday saying she arrived home to find her friends shot inside a home on South 146th Street west of Highway 99.

When medics arrived, they pronounced one of the men dead at the scene and quickly transported another man to Harborview Medical Center in critical condition.

"What I understand is approximately 50 plants or so (were found in the house). It does not appear as though this is a random crime and there may be some relationship between the victims and the suspect. As far as the marijuana grow, we don't know at this point whether it's legal or not," said Sheriff's Office spokeswoman Cindi West.

Police said one person accompanied the gunman.

The 3000 block of South 146th Street was shut down while deputies investigated.