ALPHARETTA, Ga. – Multiple lanes are shut down on GA 400 due to a serious accident with injuries on Wednesday night, the Alpharetta Department of Public Safety said. According to the Alpharetta DPS, traffic flow is reduced to one lane on GA 400 northbound between Windward Parkway and McFarland Parkway. The agency said this is due to a serious accident with injuries. It is currently unknown if more than one person is injured and what the severity of those injuries may be.