. >> and so up next, according nick billton, twitter is in a constant state of chaos, and he will talkbout jack dorsey's return. we will have much more coming up this hour. need to hire fast? go to ziprecruiter.com and post your job to over one hundred of the web's leading job boards with a single click. then simply select the best candidates from one easy to review list. and now you can use zip recruiter for free. go to ziprecruiter.com. >>> good morning, everybody. once again, i'm sue herera, and hee is the news update. the death rate has been increasing due to drug overdose and alzheimer's. the death rate rose up from 723 in 2014, and one of the few times in the last 25 years that the rate has increased. >>> four people were kill and ten others were injured after a explosion at a subway site in seoul. workers were 50 feet underground when the explosion occurred. investigation is under way. >>> and prime minister angela merkel and others were on way to open up the world's biggest tunnel. it took 17 year, and $12 billion to build. >>> in northern california a sinkhole opened up on a b