Merthyr Tydfil had ironworks which was one of the largest industries in the 19th century. Coal - mining employed thousands in the 20th Century. After coal - mining declined in the 20th Century a hoover company employed 5000 people. The factory closed in 2009 putting the last 400 employees out of work. Post - industrial the tertiary job sector of telecommunications company EE, a call centre opened up in 2013.