LYNN – The city?s plumbing inspector says the hot water in an apartment building where two young boys were badly scalded was 18 degrees above the legal limit.Firefighters responding to the incident on Wednesday called city plumbing inspector Paul Flores to the building, where Flores tested the building?s hot water temperature and said it was 131 degrees. The limit allowed under state law is 112 degrees.Flores said he will send the building?s owner, Affordable Housing Associates of Lynn, a registered letter ordering the temperature reduced.?Whoever owns the building has to bring it up to code,” Flores said.Meanwhile, a neighbor of the two boys burned by hot water said the adult attending to the children may have left them alone long enough for one of them to turn on a bathtub faucet.Charles Collins, a 263 Essex St. resident, said the boys live with their father in one of the building?s apartments across the hall from the apartment where Collins and his son, Charles, live. Collins said his son was getting the boys “ready for day care” and crossed the hallway to his apartment to use the bathroom. Collins said when his son returned to the boys? apartment, the older child had turned on the hot water.?He heard them screaming,” Collins said.District Fire Chief Stephen Archer said the 7:14 a.m. incident?s details remain under investigation. He said an 18-month-old boy had burns over 50 percent of his body, and a 3-year-old boy had burns on 80 percent of his body, including the groin and upper torso.The children were taken by emergency medical personnel to Keaney Park next to English High School and flown by helicopter to Massachusetts General Hospital.Collins said he was initially told Wednesday morning that the boys are in stable condition. His son, Charles Robinson-Collins, 21, declined to discuss the boys? injuries. He answered the door of the 263 Essex St. apartment where the children live Wednesday afternoon.?I was hysterical all morning. I?m just getting back to being myself,” he said.The building is located next to the Ingalls School and the Fayette Street fire station.Fire Chief James McDonald did not know details of Wednesday?s incident but cited American Sanitary Engineers Society research indicating 30 seconds of exposure to water temperatures of 130 degrees or hotter can cause serious burns.Charles Collins and his son and Joe Young, the man Collins identified as the boys? father, were former neighbors at 900 Western Ave., where Collins said his son got to know Young and assisted him with caring for the boys.A May 3 fire at 900 Western Ave. left building residents homeless. Collins relocated temporarily to a hotel and said Young and his children found an apartment in 263 Essex. Charles Robinson-Collins stayed with Young in the Essex Street apartment following the fire, said his father.Robinson-Collins is an athlete who plans to attend Bunker Hill Community College in the fall, his father said. He said his son “got attached” to the toddlers after helping Young care for them at their former home.?They are handsome little boys. I am praying they will be OK,” he said.