Police say the man had earlier attacked a security guard and was shot after he approached officers with the broken bottle.
The incident unfolded at about 2:45 a.m. as officers were patrolling the park in the 2100 block of N. Northlake Way and were approached by a security guard who said a transient had attacked him in the park.
The guard told officers that the man had lit a small campfire in the park and attacked the guard when he told the man to extinguish the fire and leave the park.
A crisis intervention team was called to the scene in an attempt to de-escalate the confrontation, but the man suddenly broke a glass bottle and brandished it at officers, said Patrick Michaud of the Seattle police.
Officers stunned the man with a Taser - twice - but it did not stop him.
The suspect, still armed with the broken bottle, then advanced on a group of officers. Two officers opened fire, striking the suspect multiple times, Michaud said.
He said the man had moved so close to the officers during the confrontation that the suspect fell on top of an officer who had stumbled to the ground after the shooting.
Witnesses at the scene told KOMO News that they heard gunshots - then silence.
"We were expecting people to be running or to be saying something, but it was dead silent after the shots. It was quiet," said witness Bo Hwang.
Medics and more officers then responded to the scene. The suspect was taken to Harborview Medical Center for treatment of critical, life-threatening injuries. He died a few hours later.
No officers were injured in the confrontation. The security guard sustained minor injuries.
The two officers who fired shots during the incident will be placed on paid administrative leave, as per standard department policy.
Gas Works Park remains closed until the investigation is over.