(Mascoutah)--Scott Air Force Base says tests have failed to pinpoint what sickened people at the mail facility at the base. Environmental tests of the mail center after a suspicious package was found Wednesday turned up "nothing of significance."

Scott Air Force Base spokeswoman Karen Petitt says that it's possible whatever sickened two workers for the US Postal Service and an Air Force serviceman had dissipated by the time tests were conducted.

Earlier in the day, Base Commander Col. Michael Hornitscheck said it's possible the package could have been a "very benign shipment" and that "something could have spilled or broke."