Tarenni Colliery 1858, when the Primrose Colliery was owned by Morgan and Lewis, fumes of an engine boiler suffocated 14 men and boys, and 7 horses. According to HM Inspectorate of Mines and Quarries data, outside the Gwendraeth valley, Tarenni Colliery had the highest set of recorded incidents for coal damp and methane gas explosions. In total during its production lifetime, there were six outbursts in which three men lost their lives: one on 12 December 1914; two on 17 February 1941. On 1 November 1909, water from the abandoned Ynysgeinon pit caused the death of five miners at Tarenni No.2. On
Merrimack Valley gas explosions was shut off; electricity to portions of the three communities was also interrupted to avoid igniting any lingering gas. Thousands of people were told to shut off their gas service and evacuate their homes. In Lawrence, Mayor Dan Rivera urged residents in the city to move north of the Merrimack River. Schools and senior citizen centers were opened up in all three areas to take in the evacuees, and hotels offered shelter as well. The number of people evacuating by vehicle soon caused gridlock on streets that were already experiencing congestion by the afternoon rush hour commute. Merrimack College evacuated