They took all his money.
Chinese migrant labourers usually pay very large amounts of money to manpower agencies (aka slave traffickers) when coming to the country to work. Often they have mortgage their and the families' homes to make the payment and as a result they have to work for months and sometimes years almost without pay, in order to return the loan. During the weekends, when the "official" construction sites lay idle, they tend to do their own thing, painting homes and doing small repair jobs to at least have some money in their pockets. They often carry around all their savings, as banks for a number of reasons are not really an option for them.
Thus, they become easy targets for muggers and robbers. As the Chinese labourers usually have work visas, they can go to the police, which is what happened in this case. Three arrests have been made. I just hope the victim will get his hard earned money back.