As wax begins melting onto the ground and bouquets of flowers pile up nearby, residents of China's Kunming city mourn. They're gathered in front of a train station where officials say knife-wielding attackers stabbed 29 people to death and injured more than 130 others. A migrant worker from a neighboring province explains the vigil. (SOUNDBITE)(Mandarin) MIGRANT WORKER WU BAO SAYING: "The 3.1 represents March the 1st for the compatriots who left us yesterday. It's hard to express. Of course I feel terrible, everyone feels terrible." Security maintained a heavy presence around the station on Sunday evening. The area by ticket offices where the attack took place remained closed off. A pile of unclaimed traveling bags still lies on the floor. Back at the vigil, the grief continues. (SOUNDBITE) (Mandarin) SECURITY GUARD RESIDENT CHEN BING SAYING: "I'm from Kunming. Yesterday I came back from outside the city and I heard about this