The 1980s saw an emphasis on materialism and making money in the US as the economy recovered from the 1970s crisis. Drug abuse, especially of cocaine and crack cocaine, increased in urban areas. The AIDS epidemic emerged and spread rapidly through unprotected sex and needle sharing, though the Reagan administration was slow to address the crisis. Major celebrity deaths included John Lennon and Pope John Paul II, who survived an assassination attempt. The space shuttle Challenger exploded after launch in 1986.