A Vermont man convicted of manslaughter in a fatal explosion at a New Hampshire gunpowder plant is being prosecuted on federal wire fraud charges in Maine. Craig Sanborn — formerly of Maidstone, Vt. — was sentenced in November to 10 to 20 years in prison for the 2010 explosion that killed two workers at the Black Mag plant in Colebrook. The federal indictment alleges that Sanborn, who opened a munitions plant in Brownville in 2005, fraudulently obtained $300,000 in federal community development block grant money by submitting fake invoices.