Table:
text: Rhondda
Mining disasters
Mining disasters in the Rhondda Valley 1850 - 1965
Colliery Location_ Date_ Year_ Death_toll cause
Maerdy Colliery Maerdy 23–24 December 1885 81 gas explosion
National Colliery Wattstown 18 February 1887 39 gas explosion
Tylorstown Colliery Tylorstown 27 January 1896 57 gas explosion
National Colliery Wattstown 11 July 1905 120 gas explosion
Cambrian Colliery No.1 Clydach Vale 10 March 1905 34 gas explosion
Naval Colliery Penygraig 27 August 1909 6 cage fall
Glamorgan Colliery Llwynypia 25 January 1932 11 firedamp
Blaenclydach Colliery Clydach Vale 25 November 1941 7 runaway trolly
Lewis Merthyr Colliery Trehafod 22 November 1956 9 gas explosion
Cambrian Colliery Clydach Vale 17 May 1965 31 gas explosion

Question: What year does Rhondda have a firedamp cause and a death toll greater than 11?

Question: Which colliery in Rhondda has a death rate of 7?