Someone drove up to a gas pump at a Fred Meyer store at 12906 Bothell-Everett Highway at about 5:45 a.m. and placed the pressure cooker on the pavement before driving away. An employee called 911.
A bomb squad detonated the pressure cooker about 8 a.m. to determine it was an inert device that contained no explosives.
"Bomb technicians determined the pressure cooker contained no explosive or detonation devices and had been placed in a public area to instill fear and alarm due to the date and as a replication of the Boston Marathon bombings," Everett police spokesman Aaron said in a statement.
Everett police are reviewing surveillance video and asking for tips to help find the hoaxer.
The area was briefly evacuated and the highway was closed for about 10 minutes as the bomb squad evaluated the device. The highway and businesses have now reopened.