A song by XXXTentacion is topping the charts a week after his death.<br />CNN reports "Sad!" moved from No. 52 to No. 1 on Billboard 's Hot 100 chart.<br />The song is the first posthumous No. 1 since The Notorious B.I.G.'s "Mo Money Mo Problems" in 1997.<br />The 20-year-old rapper, whose real name was Jahseh Onfroy, was fatally shot in Florida last week.<br />Authorities made an arrest days later and charged the suspect with first-degree murder. <br />
