SAUGUS – Firefighters got to work early Friday when a blaze broke out on Bow Street just after 6 a.m.Capt. Daniel McNeil said firefighters responded and before long rang the second alarm.”The fire had gotten into the walls and went through the roof,” he said.Lynn, Malden, Revere and Wakefield responded to help out.McNeil said the house was vacant and had been for some time.”It was for sale, no one’s lived in it for awhile,” he said.Arson investigator Capt. Thomas Nolan is investigating the blaze along with the Fire Marshall’s office. McNeil said the thought is the fire was electrical, but nothing has been determined.While the house is still standing, McNeil said it would likely be considered a total loss.”The fire went through the walls and the back of the roof,” he said. “The way they look at things, it would probably be considered totaled.”