SPOKANE -- A hazardous materials team discovered a grainy, metallic substance was not harmful that was found on a threatening letter sent to an attorney at Washington Trust Bank at the intersection of Sprague and Post in Downtown Spokane.

KREM 2

Authorities have responded to a suspicious letter recovered at Washington Trust Bank at the intersection of Sprague and Post.

Authorities say individuals who came into contact with the letter were isolated to be tested.

More than 400 workers are estimated to be in the building, but only a few came in contact with the letter.

The letter was sent to an attorney at the Lukins and Annis Law Office in the fourth floor mailroom.

KREM 2 NEWS called workers at the Lukins and Annis Law Offices located inside the Washington Trust building. They said authorities told them they could leave the building, but could not come back inside once they left. Workers said they were trying to go about their business as usual under the circumstances.

Sprague was closed between Howard and Post for about two hours.

On Thursday, authorities had to evacuate the Downtown Spokane post office after a threatening letter with blood stains was recovered. The letter was mailed by a Florida inmate who has a history of such behavior.

Spokane Police and the local postal inspector are investigating both cases, but not said anything about a link between the two letters.