into a giant real estate rental company, starwood/waypoint. cofounded by a billionaire friend of president trump. tens of thousands of families live in those properties, paying rent. but the company is now dogged by complaints of shoddy maintenance and an aggressive eviction policy. abc's chief investigative correspondent brian ross tonight. >> reporter: in dallas, texas, disaster in the living room, after carlos and ebony january say the landlord did a shoddy job of repairing an upstairs leak. >> we're just lucky to be alive. >> reporter: in broward county, florida, the parents of brielle nicholson say, in a lawsuit, their daughter's asthma was caused by the very same landlord who failed to remove toxic mold from their rental home. >> every morning and every night, she has to take a breathing treatment. >> reporter: the landlord was, in effect, one of president trump's best billionaire friends, tom barrack, who until he sold his interest, helped run what has now grown into a giant corporation, operating under the