Five firefighters were injured and two warehouses burned to the ground in a Wednesday morning blaze, leaving Seaford residents with lingering effects of the fire in the local air and water supply.

Firefighters responded to the scene about 7 a.m. in an industrial park in the 500 block of Harrington St. There, they found smoke and flames coming from two "warehouse/storage structures," according to the Delaware Office of the State Fire Marshal. The fire also damaged other structures in the area.

Five firefighters were treated and released with burns and other injuries, according to a Seaford Volunteer Fire Department Facebook post. No other injuries were reported.

Damage is estimated at $1 million, the fire marshal's office said.

The fire marshal's office is investigating the origin and cause of the fire, and anyone with information should contact 302-856-5600.

Around 5:30 a.m., about an hour and a half before the warehouse fire, firefighters responded to an electrical emergency at the same address. Seaford Volunteer Fire Department Chief Jack Wilson said that incident involved downed electrical wires, but he did not know if it was at all related to the warehouse fire.

"Some issues" with fire hydrants were a factor in firefighters' response to the warehouse fire, according to both Wilson and Seaford City Manager Charles Anderson.

One of the closest fire hydrants to the scene was located on a dead-end road, which, in the gravity-fed system, results in the low pressure for fire hoses, Wilson said. In addition, a hydrant at Shipley and Harrington Streets was out of service.

"Unfortunately, the location of the building put it quite a way off the road from available fire hydrants," Seaford Public Works Director Berley Mears said in a statement. "As a result, multiple hydrants were used from distances further than desirable."

"We had (a hydrant) that was hit by a vehicle," Anderson said. "They're hard hydrants to work on because they're on state-maintained roads so you have to get permits."

Firefighters ended up using water from both city hydrants and the Nanticoke River to extinguish the fire, Wilson said.

Seaford residents reported "experiencing issues with floating ash debris, air quality and dirty water," city spokeswoman Trish Newcomer wrote in an email blast around 11 a.m.

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Air quality is being monitored by the Department of Natural Resources and Environmental Control, Newcomer said, "but there are no concerns from hazardous chemicals."

She recommended residents close windows and turn off HVAC units to prevent smoke and soot from entering homes. For those experiencing "dirty water," she recommended turning on an outside spigot and letting the water run until it clears.

Shannon Marvel McNaught reports on Sussex County, Delaware, and beyond. Reach her at smcnaught@gannett.com and on Twitter @marvelmcnaught