SAN DIEGO -- A fast-moving two-alarm fire that destroyed a pair of Miramar businesses and left a firefighter with a minor injury was sparked by an electrical problem, a San Diego Fire-Rescue Department official said.

The blaze inside a 10,000-square-foot building that houses The Natural Touch and Patio Source at 9050 Kenamar Drive was reported around 8:20 a.m., the SDFRD's Maurice Luque said.

Firefighters who responded to the scene could see smoke and flames from up to five miles away, Luque said.

"When we got there, the building was well-involved in flame, so we went to defensive mode to protect neighboring buildings," Luque said.

Rebecca Jackson, general manager of The Natural Touch, which designs silk flowers, told local media that she noticed something was wrong and went into the showroom to see smoke near the ceiling -- and then flames.

"(The building) burned in like 10 minutes," Jackson said.

It took fire crews about an hour to completely douse the flames.

The fire, which was caused by an electrical failure in a lighting system, resulted in $2.5 million damage: $1.7 million in damage to the building and $800,000 to the contents, Luque said.

"The building had no sprinklers," Luque said. "Had it had them, this fire would've caused minimal damage."

Sprinklers were not required in the building, which did have smoke alarms, he said.

The fire also spread quickly because the products of the business were stored in numerous cardboard boxes, he said.