A man was killed in a house fire in Brentwood on Monday morning, fire officials said. East Contra Costa County fire crews responded at 7:33 a.m. to the blaze in the 3700 block of Concord Avenue. East County fire spokesman Steve Aubert said firefighters found heavy smoke and flames coming from the windows when they arrived. They had the fire out by 8:21 a.m. and later found the body of a man inside the house. The Contra Costa County Coroner’s Office didn’t release the name of the victim, pending notification of his family. Officials were investigating the cause of the fire.