CENTRALIA, Wash. - Two men were arrested Friday in connection with an explosive device found last month alongside railroad tracks leading to a coal-fired power plant.

Patrick Eberle, 29, and Robert McGee, 44, both of Napavine were arrested after an investigation by Lewis County sheriff's detectives.

The device, which contained powder inside a five-gallon propane tank, had the potential to deliver "an incredible amount of destructive power," said Lewis County Sheriff Steve Mansfield. It was found Aug. 20 about a mile from the Trans Alta power plant by an employee.

Eberle told detectives he made the bomb device for the 4th of July, but the device did not detonate as planned at that time.

Eberle said he put the device in his car a few weeks later and was planning on transporting it to a location where he could dump it, deputies said. He was frightened when he saw a security guard near Trans Alta and disposed of the device quickly, alongside the railroad tracks.

Eberle admitted to detectives that he did see news breaking about the incident but said was too scared to call the Sheriff's Office to tell them what had happened.

McGee was arrested on suspicion of providing Eberle with the blasting cap found on the device.

Both men have been booked into the Lewis County Jail for unlawful possession of explosives and Eberle will also be facing trespassing charges.

The device is still at the Washington State Patrol Crime Lab for evidence processing.

Mansfield said detectives at one point were exploring the possibility that the bomb was intended to damage the coal-fired Trans Alta power plant.