Prior to the Labour Day march on 1 May 2023, Yang Hoe-Dong, a district leader of the Korean Construction Workers Union (KCWU), was charged with obstruction of business, coercion, and extortion. Yang was one of the 950 union officials summoned by the police during the special investigation used to criminalise trade unions and their members. Currently 16 of those investigated are detained with criminal charges. On 1 May 2023, Yang set himself on fire to protest harassment of trade unionists by government authorities. He passed away from severe burns.