An investigation by police and the FBI in Seattle, Wash., has disproved reports of a possible nerve gas attack against downtown Seattle at the end April, The Seattle Times reported April 11. Seattle Police Chief Gil Kerlikowske reportedly said authorities had seriously investigated the threat — from an unnamed group — even though it was based on weak information. The threat purportedly involved the use of the deadly nerve agent VX, which has the consistency of motor oil and works by causing all of the involuntary muscles in the body to contract. VX is regarded as the deadliest nerve agent created to date; as little as 10 milligrams is enough to kill an average person.