. >>> it's cald the silent killer, taking the lives of patrick swayze, michael landon, and so many more. by the time it's found it's usually too late. tonight there's new hope in detecting pancreatic cancer. >>> and sleepless in america. millions tossing and turning and surfing in bed. we'll show you what staring at those screens is doing to your brain and why they're keeping you from a good night's sleep. "nightly news" begins right now. >> announcer: from nbc news world headquarters in new york, this is nbc "nightly news" with lester holt. >>> good evening. we begin with an apology today from the boston marathon bomber. dzhokhar tsarnaev breaking his silence more than two years after the attack that killed three people and injured more than 260. "i am sorry for the lives that i've taken," he told a courtroom filled with survivors and families of victims. his words, however, too little too late for the judge, who following a jury's verdict formally sentenced the 21-year-old to death. pete williams has covered the story since that awful april day in 2013 and was inside the courtroom tod

taking the lives of patrick swayze, michael landon and so many more. by the time it's found it's usually too late. tonight there's new hope in detecting pancreatic cancer. >>> and sleepless in america. millions tossing and turning and surfing in bed. we'll show you what staring at those screens is doing to your brain and why they're keeping you from a good night's sleep.

. >>> it's cald the silent killer, taking the lives of patrick swayze, michael landon, and so many moreme it's found it's usually too late. tonight there's new hope in detecting pancreatic cancer. >>> and sleepless in america. millions tossing and turning and surfing in bed. we'll show you what staring at those screens is doing to your brain and why they're keeping you from a good night's sleep. "nightly news" begins

. >>> it's called the silent killer taking the lives of patrick swayze michael landon and so many more. by the time it's found it's usually too late. tonight there's new hope in detecting pancreatic cancer. >>> and sleepless in america. millions tossing and turning and surfing in bed. we'll show you what staring at those screens is doing to your brain and why they're keeping you from a good

landon? >> hey, tracy. that's right. pinterest is launching viable pins in the next few weeks letting users buy from the viable app. pinterest retail partners include macy's, nieman marcus nordstrom, michaels and joanne's fabrics. you can pay with credit card and apple pay. it will be available on apple devices and android. stocks fell on tuesday but close off the lows as investigators remain concerns about the death crisis. the trade deficit and the services or nonmanufacturing sector. it's falling 28 points to 1801. nasdaq down to 5076. >> landon dowdy with cnbc thanks. >>> now your "nbc 10" first alert weather. >> good morning. we are seeing light rain moving into parts of our area. temperatures still going to stay chilly and below average. you can see the low hanging clouds there. i am tracking warm temperatures and a warmup on the way. >>> right now, guys we're looking live at route 202 around paoli pike. you can see no rain actively falling on this screen. northbound, southbound no problems. we have a roadblock on kelly drive. i'll tell you exactly where it is and how to get around it coming up. >> reporter: i'm matt delucia live in chester. three fires in four days. we have neighbor