Detectives are investigating a fire that broke out in an office building at East Hampton Indoor Tennis on Saturday morning — the second fire at the complex this year. At 5:01 a.m., the East Hampton Fire Department was called to an automatic fire alarm inside a building that houses the complex's office at 174 Daniel's Hole Road, near the East Hampton Airport. Brian Stanis, the second assistant fire chief, arrived to find "a heavy smoke condition" coming from the building, according to Chief Gerard Turza. He called for the rest of the Fire Department to respond. "Firefighters found the remnants of a fire inside of the structure that had been contained by the building's fire sprinkler system," Chief Turza said. He would not comment about the extent of the damage. There were signs of minor exterior damage to the building, including darkened siding, a blown out window, and damage to the door.The chief would only say, "The cause and origin of the fire is currently under investigation by the East Hampton Town Fire Marshal's office."Police set up yellow crime scene around the building. Suffolk police detectives were on scene, along with East Hampton Town police and the fire marshal. East Hampton Village Ambulance Association were also called to the fire. No injuries were reported, though. East Hampton firefighters responded to a fire in a different building in the East Hampton Indoor Tennis complex in January. A corroded pipe leaked gas into a wooden building and, at the time, investigators said that it appeared that when a heater went on, it ignited the gas. There was extensive damage to that building, which was quickly repaired. The other buildings, including a bowling alley and sports bar that were being built on the property and have since opened, were not damaged.It was business as usual at East Hampton Indoor Tennis and the Clubhouse Saturday morning. Scott Rubenstein, the managing partner, could not immediately be reached for comment.