Trying to prevent deadly explosions, the Federal Emergency Management Agency has sent contractors to more than 100,000 government-issue trailers on the Gulf Coast to paint stove knobs a distinctive red.

FEMA spokesman Aaron Walker said the change will help trailer residents tell the difference between the knobs that control the igniters and those that operate the burners on propane stoves.

Walker said four gas- or stove-related fires in FEMA trailers have been reported in Louisiana, including one in April that killed a man in Slidell. He said FEMA has had no reports of gas or stove fires in Mississippi.

Investigators blamed the deadly explosion in Slidell on propane that leaked from the trailer’s stove when the knobs for two burners were left switched on.

Walker said workers in Mississippi have painted the knobs on about 85 percent of the 30,000 to 40,000 trailers there. In Louisiana, around 20 percent of the knobs in 70,000 trailers have been painted red.

The task is time-consuming because trailer occupants must be home for the work to be done, Walker said.

He had no estimate on how much it will cost FEMA.

The plan seemed like a waste of time and money to Vica Dees, a Biloxi resident whose stove knob was painted last week.

“It was just odd,” she said. “I know what that knob is for. If it was that big of a hazard, they should have replaced it before they gave us the trailer.”

FEMA scrapped its initial plan to replace black knobs with red ones. “We found out there are not enough knobs out there to get the job done in a timely manner,” Walker said.

Gulfport Fire Chief Pat Sullivan said his department has responded to dozens of fires in FEMA trailers since last year’s storm — some caused by propane leaks, others by faulty wiring, cigarettes or food left in the oven or on the stove too long.

“You’ve got to give FEMA credit,” Sullivan added. “They’re taking immediate action because they evidently have identified a problem.”