By William Tauro
Early Friday afternoon, a Cataldo Ambulance transportation bus while in traffic burst into flames on Prospect Stret just past Webster Avenue at Bennet Court directly across the street from Dunkin Donuts.
Uniformed Somerville Police Officer James McNally while on a detail at a construction site next door noticed the flames and immediately alerted the driver who was unaware of the fire but escaped the vehicle without injuries.
No other passengers were in the bus.