SOUTH PORTLAND — A fire at a six-story apartment complex for seniors and disabled adults displaced several residents early Saturday evening.

South Portland Fire Capt. Robb Couture said firefighters responded to an automatic alarm at about 5:40 p.m. at Mill Cove Apartments on Soule Street near the corner of Broadway and Cottage Road. The department also fielded several phone calls about a fire on the second floor shortly thereafter.

When crews arrived, Couture said, they found an active fire inside an apartment on the second floor. The fire was extinguished quickly and damage was limited to that apartment, the captain said, but several other apartments sustained water damage.

“The sprinkler system is designed to keep any fire in check,” he said. “The problem was that the sprinkler in that apartment did not activate.”

The 82-unit apartment complex is managed by the South Portland Housing Authority. Couture said representatives were on the scene assisting residents but no one was available to speak to a reporter. Couture did say that several tenants would likely not be able to return to their apartment Saturday night but he didn’t know how many.

“I know they’re working to get it cleaned up as quickly as possible,” he said. “There is far more water damage than fire damage.”

The fire is not believed to be suspicious, Couture said, but investigators had not yet determined a cause. No one was injured in the fire, although one resident was taken away by ambulance for unrelated reasons while firefighters were there, the captain said.