San Bernardino train disaster facts for kids

The San Bernardino train disaster, also called the Duffy Street incident, involved two big accidents. Both happened in San Bernardino, California. First, a train went off its tracks on May 12, 1989. Then, a petroleum pipeline next to the tracks burst on May 25, 1989. This pipeline was damaged during the cleanup of the train wreck.

The Train Derailment

On May 12, 1989, at 7:36 a.m., a Southern Pacific freight train had an accident. It had six locomotives and 69 cars filled with a mineral called trona. The train was going down Cajon Pass when it lost control. It then derailed, meaning it went off the tracks. The train crashed into houses on Duffy Street. This area is near where the 210 Foothill Freeway crosses the Cajon Creek.

The train's conductor, a brakeman, and two people living in the houses died in the crash. Seven houses on Duffy Street were completely destroyed. The front locomotives and all the freight cars were also wrecked.

Workers in Mojave had made a mistake. They calculated the train's weight incorrectly. Also, the engineer at the front of the train did not know that one of the helper engines at the back had broken dynamic brakes. Dynamic brakes help trains slow down on hills. Because of these problems, there wasn't enough braking power to control the train's speed.

When the helper engineer realized the train was going too fast, he tried to use the emergency brakes. But this action turned off the dynamic brakes. The train then became a "runaway train," meaning it was out of control. It reached a speed of about 100 miles per hour (mph). The train then derailed on a curve meant for 35 mph. The locomotives and cars crashed into the houses below, destroying them.

Investigators looked at the locomotives' "black boxes," which record data. They found that the third locomotive's dynamic brakes were not working at all. The sound of its cooling fans made crews think they were working. It was also found that the helper engineer knew about the faulty brakes on his unit. However, he did not tell the crew at the front of the train.

The train was too heavy to control on the downhill slope. This was due to the wrong weight calculation, poor communication, and broken brakes. Once the dynamic brakes were turned off by the emergency brake, the heavy cars made the train speed up very quickly. The regular air brakes could not stop it alone. The train flew off the tracks near Duffy Street. It scattered locomotives, cars, and cargo everywhere.

The Pipeline Burst and Fire

A 14-inch high-pressure petroleum pipeline was buried six feet underground next to the tracks. It was operated by Calnev Pipeline. During the cleanup of the train wreck, stakes were put down to mark the pipeline's location. This was to prevent damage. Pipeline workers were there to watch during the cleanup of the rail cars. However, they were not present when the spilled trona was being removed.

Train service on the track was back to normal four days after the crash. Thirteen days after the train wreck, on May 25, 1989, at 8:05 a.m., the pipeline burst. This happened at the same curve where the train derailed. Gasoline sprayed into the neighborhood and caught fire. The fire burned for almost seven hours. Flames shot 300 feet into the air.

By the time the fire was put out, two people had died. Eleven more houses and 21 cars were destroyed. Five of the destroyed houses were across the street from houses ruined by the train. One house that survived the train crash was destroyed by the fire. Four other houses had moderate smoke and fire damage. Three more had only smoke damage. The total damage was about US$14.3 million. More damage came from the fire than from the train crash. However, more people died in the train derailment.

What Happened After

After the pipeline burst, people tried to get the Calnev pipeline shut down permanently. But these efforts were not successful.

Many people who lived in the area received money from Southern Pacific and Calnev. They then moved away after this disaster. The city changed the land closest to the tracks on the south side of Duffy Street. It became an open space so no new houses would be built there. Other nearby empty plots remained empty for years. However, by 2016, at least three houses had been rebuilt.

Southern Pacific also changed how it handled cargo weight. Now, if paperwork doesn't show a weight, clerks must assume each freight car is carrying its maximum load. This way, the train dispatcher will always assign enough locomotives. This ensures the train has enough braking power for steep hills.

Seven years after the accident, Union Pacific bought Southern Pacific. Union Pacific trains still use the tracks where the derailment happened.

How the Accident Was Investigated

The NTSB investigated both disasters. Most of their focus was on what led to the train derailment.

Part 1: The Train Derailment Investigation

The train was carrying trona from a mine. It was going to the Port of Los Angeles. From there, it would go by ship to Colombia. This was the second such shipment. The buyer had bought 6,900 tons of trona. The mining company used 69 large hopper cars, each meant to hold 100 tons.

When the mining company gave the paperwork to the clerk, they didn't fill in the weight. They thought the railroad would know the cars were full. The clerk filled in the weight as 60 tons per car. He guessed this by looking at how 100 tons of coal looked. So, the train was listed as weighing about 6,151 tons. This was much lighter than its actual weight.

The train crew picked up the 69 freight cars. They had paperwork showing the wrong weight. They also had a dead locomotive that couldn't start. Another locomotive was added to the front.

Later, a new train dispatcher correctly figured out the train's weight. It was about 8,900 tons. He knew that on a steep 2.2% grade, one working dynamic brake could control about 1,700 to 1,800 tons. Dynamic brakes work best around 25 mph. The dispatcher realized they needed more braking power. So, instead of one helper locomotive, he ordered two helper units to be added to the back of the train.

The two main reasons for the runaway train and derailment were:

• The crew was given the wrong train weight.
• Most of the locomotives did not have fully working dynamic brakes.

Each hopper car had regular air brakes. These brakes use metal shoes that press against the wheels to create friction. Air brakes work best at speeds under 25 mph. At higher speeds, they create more heat than stopping power. The air brakes on the heavily loaded cars had limited effect. They became weaker and hotter as the train sped up.

The second locomotive at the front was dead. So, its dynamic brakes didn't work. The third locomotive's dynamic brakes also didn't work. The fourth locomotive's dynamic brakes worked only sometimes. One of the two helper units at the back also had broken dynamic brakes. This meant only two locomotives had fully working dynamic brakes. This information was not given to the train dispatcher.

The train engineer knew only that one front locomotive had no brakes. He thought he had enough dynamic brakes for 6,151 tons. But with the true weight of 8,900 tons, the train needed more working dynamic brakes.

As the train started downhill, the engineer realized he couldn't control its speed. He tried to use the air brakes and the working dynamic brakes. He asked the helper engineer to help. But he didn't know the helper had only one working dynamic brake. As a last try, the helper engineer used the emergency brake. This action, however, turned off all the dynamic brakes on the train.

With only the air brakes working, the train sped up even more. The air brakes got so hot they started to melt. When investigators arrived, they saw the wheels were so hot they had expanded off their axles.

The train was going about 110 mph when it entered a curve meant for 40 mph. It derailed and crashed into the houses. Almost all the houses on the track side of Duffy Street were destroyed. The one house that survived the derailment was destroyed in the pipeline fire. Over 600 feet of track were also ruined.

The NTSB report said that if the train had started downhill slower, the crew might have regained control. The report also found that Southern Pacific's training did not teach how to stop a runaway train. The railroad's control over mountain operations was not good enough. The report concluded that the derailment was unavoidable due to many unfortunate events. The engineers were not blamed.

Part 2: The Pipeline Damage Investigation

Initial checks of the pipeline found no damage from the train wreck. So, it was thought safe to refill the pipeline with gasoline. This pipeline supplied Las Vegas, so Calnev felt pressure to restart the flow quickly. A resident even said that serving Las Vegas was more important than their California town. The pipeline operators watched the first flow. Since there was no leak, they thought everything was fine.

After Calnev's first check, the cleanup of the train wreck began. The hopper cars were removed first. Then, the locomotives were removed, and damaged houses were torn down. Over 600 feet of track were rebuilt. An excavator was used to remove the spilled trona. This started on May 16 and ended on May 19, six days before the pipeline burst.

Even though stakes marked the pipeline's path, the cleanup still damaged it. Investigators found deep cuts that were made by a backhoe during the cleanup. Over time, these cuts weakened the pipeline. This caused it to burst. During cleanup, Calnev only checked small parts of the pipeline. They checked where train wreckage had landed on the pipe. They did not dig up the entire pipeline along the derailment site for a full check. They also didn't do a hydrostatic test, which uses water pressure to find damage. If they had done these, the damage would have been found, and the burst could have been prevented.

Right after the pipeline burst, operators saw a sudden change in pressure. This meant a leak or rupture. But they didn't act quickly to stop the flow of gasoline. Also, the valves downstream from the rupture failed to close. This allowed more gasoline to flow back down the pipe, making the fire worse and last longer. These valves were already faulty before the derailment. They were not fixed in the two weeks between the train crash and the pipeline burst.

During the pipeline inspection after the burst, more train wreckage was found near the rupture point. At that spot, the pipeline was only buried 2.5 feet deep. This was much closer to the surface than it was at the time of the derailment.

In Popular Culture

The disaster was shown in "Runaway Train," an episode of the Canadian TV series Mayday. This episode was part of Season 3 (2005) and was also called Crash Scene Investigation. In the United States, it was broadcast with the title "Unstoppable Train."

Images for kids

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  Sketch of the accident site

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  Duffy St. train disaster San Bernardino California May 12, 1989

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  Locomotives

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  Buried house on Duffy St.

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  Destroyed house on Duffy St.