Aurora officials have threatened to imminently close two long-troubled apartment complexes at the center of a national firestorm unless their owner takes quick and immediate steps to address crime and deterioration of the properties, according to letters sent to the owners that were obtained by The Denver Post on Thursday.In two letters sent Sept. 20, Aurora Police Chief Todd Chamberlain told CBZ Management and its Colorado owner, Zev Baumgarten, that two complexes on Dallas Street the Edge of Lowry and 200 Columbia apartments are criminal nuisance properties. Chamberlain told Baumgarten and CBZ that he would authorize a civil proceeding directing the properties be closed as soon as Sept. 30 if problems there arent addressed.This week the city also issued a municipal court summons to Baumgarten because of a litany of health code violations related to another CBZ property in Aurora, the Whispering Pines complex on Helena Street, according to a copy of the summons obtained by The Post. Its at least the third municipal summons issued against Baumgarten in recent years because of CBZs failure to fix conditions at its Aurora properties, and the inspection and summons triggered fears among Whispering Pines residents that their homes could be shuttered next.In one of his letters to CBZ, Chamberlain wrote that the uptick in violent crime and the physical condition of the properties present a significant public safety concern. One call for service placed last month at 200 Columbia was for murder, according to the letter. Chamberlain also noted the extensive criminal call history, at the Edge of Lowry apartments, the property that sparked a national firestorm about gang takeovers last month after a resident shared video of armed men in her hallway.Chamberlain also noted numerous violations issued to CBZ over the condition of the properties. Those violations, Chamberlain wrote, have not yet been addressed.Read more from our partners at The Denver Post.