Hutchinson ? Fire officials said a lightning strike may have caused the raging prairie fire that burnt across 5,400 acres in central Kansas and forced the evacuation of 300 people on Thursday.

Gov. Kathleen Sebelius declared Reno County a disaster emergency as the blaze neared homes in northeast Hutchinson, and requested federal aid to cover firefighting costs.

Local crews are now tallying up their receipts from the massive effort to contain the fire, and state officials hope the Federal Emergency Management Agency will reimburse the county for some of its costs.

As crop dusters flew overhead to drop water on the flames, firefighters from Harvey, Sedgwick, Marion and Rice counties battled the blaze, which spread quickly across the prairie toward inhabited areas.

Residents in a 21 square-mile evacuation area west of the Hutchinson Airport worked to save their homes until authorities forced them to leave Thursday night when several propane tanks exploded.

Weary fire crews worked through the night to contain the fire and were still active Friday morning.

Sebelius’ state of disaster emergency declaration won’t help reimburse affected communities and residents directly.

However, it does mean that the state pays for overtime hours state government employees worked as a result of the fire.

If Reno County qualifies for federal assistance from FEMA’s Fire Management Assistance Grant Program, those additional funds would cover 75 percent of the county’s fire-related costs.

To get the grant, Reno County officials need to demonstrate that fire-related costs were at least $158,617, or that spending on the fire has exceeded $500,000 since the beginning of the year.

Hutchinson Fire Chief Kim Forbes said it would take several more days to compile overtime costs and expense reports, but local emergency officials said Friday the cost of fighting the fire was already above $158,617.