UPDATE 11:42 a.m.: The fire is reportedly under control.
Lower Merion Township firefighters were called to 545 Greystone Road in Merion Station around 9:30 a.m. to put out a two-alarm fire.
Reports said the rear of the house was engulfed by a possible basement fire. Flame and smoke engulfed the first and second floors as well.
Nearby Bala Cynwyd's Union Fire Associaton and an ambulance from Narberth were among the units initially deployed. By 10:30, companies from Belmont Hills, Bryn Mawr, Gladwyne and Narberth arrived on scene along with Lower Merion Police and Fire Command.