When the evictions failed to end the strike, the Rockefeller interests hired private detectives that attacked the tent colonies with rifles and Gatling guns. The miners fought back, and several were killed. When the tenacity of the strikers became apparent, the Rockefellers approached the governor of Colorado, who authorized the use of the National Guard. The Rockefellers agreed to pay their wages.
At first, the strikers believed that the government had sent the National Guard to protect them. They soon discovered, though, that the militia was under orders to break the strike. On April 20th 1914, two companies of guardsmen attacked the largest tent colony of strikers near the town of Ludlow, home to about 1,000 men, women, and children. The attack began in the morning with a barrage of bullets fired into the tents. The miners shot back with pistols and rifles.
After a strike leader was killed while attempting to negotiate a truce, the strikers feared the attack would intensify. To stay safe from gunfire, women and children took cover in pits dug beneath the tents. At dusk, guardsmen moved down from the hills and set the tent colony on fire with torches, shooting at the families as they fled into the hills. The true carnage, however, was not discovered until the next day, when a telephone linesman discovered a pit under one of the tents filled with the burned remains of 11 children and 2 women.