A Monday night fire caused extensive damage to the back of a vacant fourplex being remodeled in Cheyenne.

Cheyenne Fire Rescue spokesman Scott Smith says crews were called to the fire in the 1600 block of Seymour Avenue shortly before midnight.

"When they arrived on scene around 11:56 p.m. they saw flames visible from the rear of the structure," said Smith.

"The residence was a single-family home that was converted into apartments which provided challenges for our firefighters searching the structure," he added.

Smith says the fire was contained to the back of the residence and did not spread to other parts of the structure.

The cause of the fire remains under investigation.