Lawrence firefighters arrived to find heavy fire showing from a large 2 1/2 story woodframe multi family dwelling. Command quickly struck a 2nd alarm bringing in mutual aid to the scene and to cover. Due to the heavy volume of fire, companies were forced to go defensive and command struck a 3rd alarm. Multiple ladder pipes and big hand lines were used to knock down the heavy fire and keep the fire from extending into the exposures. Companies remained on scene for several hours checking for hot spots.