hickox was working with doctors with no borders. she was stopped at the airport and was quarantined. >>> we have the latest on a medical accident. three of the victims now face possible permanent brain damage. the study involved 90 healthy volunteers all of them given various doses. >>> an accident is in yonkers is causing major back ups. >> reporter: you can see these cars sandwiched together and this is just three of them but that middle car literally underneath the car in front of it. two other vehicles involved in this accident as well. and we know do know that two people were injured. nonlife threatening injuries. what you need to know navigating these areas. the problem is that exit ramp is shared with the exit for the parkway. you, that's the north side of into this accident. look at this stream of head lights going north on that bronx city parkway. this is the volume you have to deal with. it does not affect you if you're coming off the saw mill river highway. but a mess tonight. shannon sloan, channel 7 eyewitness news. >>

kaci hickox was stopped at a new york airport after coming in contact with ebola patients last year. she was ordered to stay in quarantine in a tent against her will. the lawyer for governor chris christie and the state health public's interest and are immune from lawsuits over quarantines. >>> christmas, yes, was three weeks ago but you might not know it walking around the city. you probably noticed dozens of these discarded trees littering the sidewalks. is it taking longer than usual for the sanitation crews to pick up? we sent andrew siff in search to find out. >> reporter: here in the bronx they're full ching and recycling thousands of christmas trees on what's supposed to be the last day of the program. the whoop chippers are chipping away. but on the sidewalks of new york, it's beginning to look a lot like, well, january 15th. >> i just want it off my lawn. >> 21 days after christmas. some new yorkers are wondering why there are still trees on so many sidewalks. letter carrier tonya lewisson said -- >> about 20 to 25 trees out amongst the routes that i have. i thought it was o