Newark NJ (Essex)4-4-4+++ Box 3537 21:24 hrs. Newark Fire Headquarters transmitted Box 3537 for a fire reported in a large 3stry frm upon arrival units found 3 3stry frms fully involved. A 2nd alarm transmitted on reports of children trapped as the first units arrived, however all searches were (-). Dep 1 requested 3rd and 4th alarms due to heavy volume of fire in main fire bldg and in exps. East Orange to scene, and Irvington to the city for covers. Fire was reported as suspicious and arson investigators were requested to the scene . There were additional special calls over the fourth alarm of 2 Engs and 1 Trk Co. Fire placed under control 23:31 hrs