>> reporter: a somber mood as tourists return to the strip after many spent the night on lockdown in their hotel rooms. >> we just sat still and kind of watched. we could see mandalay bay from our hotel room. we could see the lights and the ambulance going. >> police officers have replaced street performers. hotel marquise have gone black with thoughts and prayers as well as phone numbers to call for the missing and addresses to donate blood. it's a stark change in tone for a city glamorized in movies for wild fun. >> this is vegas. >> reporter: vegas headliners are offering words of condolences. jennifer lopez writing las vegas feeling so broken this morning. celine dion saying she's praying for victims and families. it's been nearly four decades since something like this struck