PHILADELPHIA (WPVI) -- The Federal Transit Administration is looking into how SEPTA stores its decommissioned buses.
The investigation follows the June 5 fire at a SEPTA storage yard in the city's Tioga-Nicetown section.
The massive fire damaged 40 buses, of which more than a dozen were electric.
SEPTA says it was started by a lithium-ion battery.
The FTA sent a letter to SEPTA requesting details on storage and handling procedures for buses with lithium-ion batteries. Officials also want to know about any added safety measures taken to reduce fire risk.