LANGLEY, Wash. - An arson suspect has been arrested and a federal agency has joined the investigation after flames destroyed two large homes Thursday morning on the south end of Whidbey Island, officials said.

Crews responded to the scene, in the 5700 block of Capt. Vancouver Drive, southwest of Langley, at around 6 a.m. after receiving reports of smoke and flames spewing from a home there.

One home was fully ablaze when firefighters arrived, and the flames were spreading to a second large home next door. A second alarm was sounded and crews began a desperate battle to prevent the flames from destroying the second home and to stop the fire from spreading to a third nearby home.

Three hours later, the first home was burned to the ground and the second was declared a total loss despite the efforts of firefighters. The third home sustained some exterior damage.

Island County Sheriff Mark Brown later said the fires were suspicious and that a 48-year-old man had been taken into custody on suspicion of first-degree arson.

Brown would not immediately reveal how the suspect was identified or whether he has any connection to either of the families whose homes were destroyed. But he did say that some evidence was discovered at the scene of the blaze, and that the suspect was arrested nearby. He said more details will be released by Friday.

Brown also disclosed that the the federal Bureau of Alcohol, Tobacco, Firearms and Explosives has joined the investigation into the arson.

The suspect has no prior criminal history that investigators have been able to discover, Brown said.

Both of the gutted homes are located near the Useless Bay Golf and Country Club, just north of Sunlight Beach on the southern end of Whidbey Island.

Brown said no one was seriously injured in the fires. A family friend said the occupants of the first home escaped with nothing more than the pajamas they were wearing when the blaze broke out.