The Kmart store on Northgate Drive is now closed.And that concerns nearby residents like Jennifer Mount.She lives two blocks away in what she describes as a nice neighborhood.But lately Mount and her neighbors have seen a trend developing that they fear will spread like cancer as Kmart clears out of the store for good. During the past few months nearby Kingswood Park has become a sleeping area for homeless while drug use has increased along with car and house break-ins in the general area, according to neighbors.Their fear isn’t unfounded. Manteca has a checkered past of shuttered commercial and industrial buildings turning into havens for homeless and vagrants to the detriment of nearby property owners and residents.