At approximately 0600hrs on Saturday, January 9th, Malden Fire Alarm reported a building fire at 503-505 Pleasant St, first arriving companies found heavy fire showing from floor 4, 5 and the roof area of a large 5 story U-Shaped brick apartment building and immediately struck a 2nd alarm. Subsequent alarms were struck due to the size of the building and heavy fire conditions the last and 6th Alarm being sounded at 0800hrs. I arrived at about 7am there was still heavy fire conditions in the rear of the building, 4 aerials were raised to the building and multiple hand lines as well as several blitz guns were in operation, a trench cut was made along the firewall in between the two "wings" of the U, where companies made there stand and stopped the spread of the fire. Temperatures at the time of the fire were in the low 20's. Operating at the fire were companies from Malden, Revere, Everett, Somerville, Saugus, Chelsea, Boston, Winthrop, Medford, Reading, Belmont, Wakefield, Cambridge, Arlington.