I recall hearing about a couple of carjackers being pursued by the police in San Francisco who pulled into the projects hitting an object as they did which deployed the airbags. They then ran into to project complex still chased by officers who had no trouble identifying them since they were the only people around covered with that white talcum powder like dust you described. By the way, this occurred a few years back when SFPD was still arresting criminals.
Seamus