Among the dead were the family of Charles Costa, union organizer at Aguilar, and the family of Mrs Chavez, a Mexican woman, comprising herself, two girls of 4 and 6 years old, a baby 6 months old, and a nephew, 9. The family of Costa comprised himself, his wife and two children, Lucy, 4, and Orafrio, 6. Under the mass of charred bedding at the bottom of the safety pit, from which all of the bodies were recovered, were also those of two children of Mrs Marcellino Pedrigon - Clardillo, 4, and Rogerio 6, and the three Petrucci children, Lucy, 3; Joe, 4, and Frank, 6 months. The children were clasped in each other's arms, and over them lay the bodies of the two women, both badly charred. Both of the women were to be mothers soon.
– Rocky Mountain News, 23 April, 1914

Conditions

Prior to the catastrophic breakdown in 1914 in industrial relations between striking Colorado Fuel and Iron Company miners and their paymasters, the previous summer of 1913 saw coal miners throughout Colorado working in desperate conditions that were increasingly intolerable. This was especially true for employees of the largest coal mining operation in Southern Colorado, the aforementioned Colorado Fuel and Iron Company (CF and I), which was owned by John D Rockefeller, Jr

Miners, frequently working on their knees or on their stomachs, constantly inhaling coal dust, usually had to bring their own blasting powder and drag their own timber into the mines to lay their own tracks and shore up mine walls. The time spent laying the tracks and shoring up the walls, while vital to their ability to mine coal, was unpaid labour. They were paid only based on the weight of the coal that they dug out of the earth. Company weighmen, therefore, determined how much money a worker made. It was in the interest of those weighmen to short the weight of the coal, increasing the company's profits.

The average gross wages for a Colorado coal miner was about $3.50 per day. Deductions from these gross wages included charges for explosive powder, blacksmithing, medical expenses, any outstanding bill from the company store and rent for his company-owned housing. CF and I miners took home $1.68 a day. This $1.68 was paid in company scrip, redeemable only at company stores, rather than in United States Currency. The company stores were able to set their own prices for consumer goods, and did not hesitate to gouge the miners and their families, who had no money that would be honoured anywhere else. Prices were typically about 30 percent higher than in other stores, located away from the mining camps.

Within the mining camps, some of which were incorporated as towns, police officers, doctors, ministers and teachers were all company employees. If there was a library or movie theatre, the company decided what books and films were available.

Coal miners in Colorado died at more than double the national average. Of 42,898 coal miners who died in mine accidents in the United States between 1884 and 1912, 1,708 died in Colorado mines.

Strike

In August of 1913, a labour organizer was shot and killed by men working for the coal companies. This was ruled 'justifiable homicide' by a coroner's jury that was comprised of local businessmen. On 15 September, 1913, delegates representing Colorado coal miners attending a special convention of the United Mine Workers Union in Trinidad, Colorado, voted to strike. The actual strike began on 23 September, 1913. Over 8,000 miners and their families left the coal camps and set up housekeeping in tent colonies near those camps. One of the largest tent colonies, with more than 1,000 inhabitants, was at Ludlow. Communication within the tent colony was challenging, with a total of 24 different languages being spoken by the miners living there.

The demands of the striking workers were as follows:

1. Recognition of the United Mine Workers union
2. A ten percent increase on the tonnage rate (remembering that workers were paid based on the total weight of the coal mined)
3. An eight-hour work day
4. Payment for 'dead work', such as shoring the mine, timbering and laying track
5. The right to elect their own check-weightmen, to ensure an honest measure of the amount of coal actually mined
6. The right to trade in any store, choose their own boarding places and choose their own doctors
7. Enforcement of Colorado mining laws and an end to the system of company guards at the worksite

It's worth noting that existing law already stated that the miners were entitled to items three, five and seven, as well as parts of item six.

The coal operators moved quickly, bringing in detectives from the Baldwin-Felts Detective Agency, specialists in breaking coal strikes, and 'replacement workers'. A harassment campaign was initiated against the striking miners. Powerful searchlights shone on the tent colonies at night and, more ominously, a Gatling-type machine gun was affixed to an improvised armoured car, which was dubbed the 'Death Special'.

The 'Death Special' saw its first use on 17 October, 1913. The Forbes tent colony, just south of Ludlow, was peppered with gunfire. One striking miner was killed. A child received nine bullet wounds in the leg. A total of 148 bullet holes were found in a single tent. Some of the striking miners dug pits under their tents as a place where they and their families could take refuge from gunfire.

On 26 October the county sheriff, a representative of the Baldwin-Felts Detective Agency, a contingent of mine guards and local militiamen travelled by train to Ludlow, armed with machine guns. The miners learned about the train and hid on a hill about a mile south of Ludlow. They forced the train to retreat after killing the engineer. The next day, the striking miners attacked some mine buildings where guards were stationed.

On 28 October Colorado's governor Elias M Ammons sent in the National Guard. The National Guard was to have been impartial, protecting both the mine owners' property and the striking miners. Many of the National Guardsmen, however, had been strikebreakers from an earlier coal strike in 1904. Those National Guardsmen who did not have this history had their loyalty purchased by CF and I, which stationed the troops in company buildings and gave them goods from company stores. On a visit to the strike zone, Colorado state senator Helen Ring Robinson observed Guardsmen entering CF and I Offices to receive their paychecks.

With the presence of the National Guard leading to more violence, Governor Ammons recalled most of his troops, leaving only one small company, known as Company B, assigned to patrol the Ludlow area, which had been the site of innumerable company/striker confrontations. The local coal companies created a second company, made up of loyal employees and dubbed this company 'Company A'. Company A gained official recognition almost immediately and its members were sworn in as official militia personnel.

The strike continued under these conditions, with frequent violence, through the winter and into the spring of 1914.

Massacre

At about 10am on 20 April, 1914, what sounded like two bombs were heard to explode. It is believed that the noise of these bombs was intended as a signal to the National Guardsmen to open fire, a provocation for the strikers to open fire on the National Guard, or a signal to alert the mine guards at the Delagua, Berwin and Tabasco mines, up-canyon from Ludlow, that fighting was about to commence.

Whatever the reason for the detonation of those bombs, within a matter of minutes the guardsmen of Company B and striking miners were engaged in a heated gun battle. Although the striking miners heavily outnumbered the National Guardsmen, the guardsmen had a better location and a machine gun. Members of Company A came in as reinforcements, providing a second machine gun as well as additional manpower. Estimates of the total number of National Guardsmen and militiamen on the scene range from 150 to 200. The battle lasted 14 hours.

Louis Tikas, one of the union organizers, tried to go up into the hills where the guardsmen and militiamen were located, to arrange a truce. He never returned. Tikas was arrested by Lt Linderfelt of the Colorado National Guard. Sometime after the initial arrest, Linderfelt struck Tikas with the butt end of his Springfield rifle, breaking the stock in two and fracturing Tikas' skull. Tikas was then shot three times. Reports vary on the question of whether he was trying to escape or was simply executed along with two other prisoners, James Fyler and Frank Rubino.

Many of the striking miners retreated into the surrounding hills with their families. Others sought refuge from the gunfire in the pits they had dug under their tents for that purpose. Around sunset a passing freight train stopped near the camp, positioned between the two sides involved in the battle. This allowed most of the remaining striking miners and their families to escape into the hills. Guardsmen soon forced the train's engineer to move along.

That evening, the militiamen entered the camp, began looting, and set fire to the tents. An investigation found that kerosene had been poured on the tents. The bodies of Mary Petrucci, Alcarita Pedregone and the 11 children who had died of asphyxiation in what became known as the 'Death Pit', were found the next morning by a telephone linesman who unwittingly uncovered the pit by moving the charred remains of an iron cot. The final death toll was at least 25 — including Louis Tikas, three militiamen and one uninvolved passerby.

Aftermath

On 21 April, 1914, the day after the massacre, the New York Times ran the following description of the scene:

The Ludlow camp is a mass of charred debris, and buried beneath it is a story of horror imparalleled [sic] in the history of industrial warfare. In the holes which had been dug for their protection against the rifles' fire the women and children died like trapped rats when the flames swept over them. One pit, uncovered [the day after the massacre] disclosed the bodies of ten children and two women.

On 10 June, 1914, John D Rockefeller Jr provided his own version of what happened:

There was no Ludlow massacre. The engagement started as a desperate fight for life by two small squads of militia against the entire tent colony... There were no women or children shot by the authorities of the State or representatives of the operators... While this loss of life is profoundly to be regretted, it is unjust in the extreme to lay it at the door of the defenders of law and property, who were in no slightest way responsible for it.

Remarkably, the strike continued until December, but ended with the striking miners failing in their demands and being replaced with non-union workers. After the strike ended, 408 of the miners were arrested, of whom 332 were indicted for murder. The trials lasted until 1920. The Colorado National Guard court-martialed ten officers and 12 enlisted men. No strikers or Guardsmen were convicted of any crime due to their actions at Ludlow.

The United Mine Workers' Association purchased the site of the Ludlow massacre and, in 1918, erected a monument dedicated to Ludlow's dead. The names and ages of the dead are inscribed on the monument, which also preserved the 'Death Pit', which has now been lined with concrete and into which people can walk today.

It was in 1935 that workers attained the right of being paid for 'dead work', the right to live off of company land and better housing.

In December 2008 the US Department of the Interior designated the Ludlow site as a National Historic Landmark.