The first fire in a four-month arson spree sprang to life in the aisles of a Dollar Tree store off Rollins Avenue in Rockville. The second involved a shopping cart full of trash ignited and sent down the ramp of a nearby parking garage. By the time firefighters put out the flames that damaged three buses for the French International School on April 16, nine vehicles were burned in 17 related incidents, causing $250,000 worth of damage.

Investigators announced the arrest of two Rockville teens charged with the fires Friday.