OMAHA, Neb. (WOWT) – Fire crews are working to pin down the cause of an overnight blaze at a vacant north Omaha home. OFD tells 6 News they were called to the previously-burned residence near 28th and Parker Streets around 2:30 a.m. Crews arrived and declared a working fire. The blaze was fought defensively at first, meaning only from the exterior of the home, but was declared under control quickly.