Police said the car was traveling more than 200 kph (120 mph) when the heavily intoxicated driver lost control and slammed into the bus stop Saturday, killing seven people and injuring three.
The 30-year-old driver, Alexander Maximov, had been arrested for drunken driving in 2010 and told police that prior to Saturday's accident he had been drinking for two days, Interfax said. The driver also had received two speeding tickets this year.
The orphans were returning from an awards ceremony for a city arts and crafts competition held in a park in western Moscow.
Moscow police reported Sunday morning that they had detained more than 130 drunken drivers over the past 24 hours, perhaps eager to show they were taking the problem seriously.