More than a month after a Union Pacific Railroad oil train derailed and caught fire in the Columbia River Gorge, rules are in the works to increase the safety of oil by rail.

On the same day the U.S. Department of Transportation proposed rules requiring railroads to improve their spill response planning and transparency, Oregon Sens. Jeff Merkley and Ron Wyden introduced their second bill tackling oil train safety.

On April 27, Steve Holm and three other inspectors drove right over a set of broken railroad bolts that later would cause a massive oil train explosion.

Holm rode shotgun as Union Pacific Railroad’s specially equipped pickup rolled along at 10 mph over its tracks through the Columbia River Gorge National Scenic Area.

He stared out the front windshield at the steel rails, the wood ties beneath and the plates and bolts that held them together.

The National Transportation Safety Board has responded to letter from Oregon’s senators about why it did not investigate last month’s oil train derailment in the Columbia River Gorge, saying its limited staff likely would not have gleaned any new safety recommendations from examining the incident.

The federal agency provided a 50-page response to Oregon Sens. Ron Wyden and Jeff Merkley, saying it “recognizes the impact of this accident on your constituents and understands the concerns of those affected.”

Washington state begins its public review Monday of what would be the nation’s largest oil-by-rail terminal in the country, slated to be built at the Port of Vancouver.

The hearings are one of the final steps in determining whether the project gets built.

The state will use five weeks of hearings to determine how to move forward with the Vancouver Energy Project, a joint venture backed by companies Tesoro and Savage.

It’s Union Pacific’s fault. That’s the basic thrust of a preliminary report from federal railroad regulators on Thursday. It investigates why a nearly 100-car oil train partially derailed and caught fire in the Columbia River Gorge on June 3.

OPB's Kate Davidson spoke to Sarah Feinberg, the head of the Federal Railroad Administration to learn more. The following exchange has been edited for clarity and brevity.

You can hear their full conversation by clicking play on the audio player at the top of the article.

A new report from the Federal Railroad Administration released Thursday said Union Pacific is solely responsible for an oil train derailment earlier this month in the Columbia River Gorge.

The federal rail agency said in its preliminary findings that the derailment was caused by broken lag bolts that the railroad failed to maintain, which led to a widened track that caused the 16-car derailment.

“When it comes down to it, it’s Union Pacific’s failure to maintain its track led to this incident," said Sarah Feinberg, who heads up the Federal Rail Administration.

Despite state and local calls for a moratorium, Union Pacific officials say they plan to resume sending crude oil through the Columbia River Gorge this week.

These would be the first trains carrying crude oil to pass on the Oregon side of the Gorge since the June 3 derailment in Mosier where 16 cars carrying crude oil left the tracks. The derailment spilled 42,000 gallons of crude oil and caused a fire that forced 100 people to evacuate their homes. The crash closed Interstate 84 for hours and left a small oil sheen on the Columbia River.

The U.S. Department of Energy is considering the future of a public asset worth tens of billions of dollars: the Strategic Petroleum Reserve.

Editors' note: Invisibilia's back! Each Friday for the next seven weeks, we'll feature an excerpt from the latest episode of the NPR podcast. We're also creating original features for Shots that explore the Invisibilia theme of the week. This Saturday, Hanna Rosin asks whether social norms have changed enough so that boys are no longer afraid to cry. On Sunday, we explore how the norms for sickness and health vary around the world.

Just after noon on June 3, the two-man Union Pacific crew hauling 96 cars of Tacoma-bound crude oil felt a tug on the train as they passed through the Columbia River Gorge.

The train’s emergency brakes triggered unexpectedly, according to railroad union leaders, indicating bad track or equipment failure could be to blame. The crew looked back and saw smoke — the beginnings of a fire that would burn for much of the night.

A year before 16 of its oil tanker cars derailed and caused a fire, a spill and an evacuation order in the Columbia River Gorge, Union Pacific lobbied against stronger oversight of oil trains moving through the Northwest.

The railroad industry lost in Washington. But in Oregon, it won.

Tribal leaders from around the Northwest gathered Thursday in Mosier, Oregon, not far from the site of last week’s oil train derailment in the Columbia River Gorge.

They prayed and spoke out against oil trains.

“We should not have any fossil fuels coming through our ancestral homeland, especially along the river," said Austin Greene, the tribal chairman for the Confederated Tribes of Warm Springs.

Washington Gov. Jay Inslee wants oil trains to slow down and safety improvements to speed up. Inslee said Wednesday that he personally delivered that message to the CEO of Union Pacific and the executive chairman of BNSF over the last 48 hours.

oil train, transportation
Flickr Photo/Russ Allison Loar (CC BY NC ND 2.0)/https://flic.kr/p/aqtNAn

The oil train spill June 3 in Mosier, Oregon was the latest of about 20 oil train derailments in the US since 2013. The group Earth Justice tracks derailments and spills with an online map.

One Washington lawmaker says there's a way to limit the danger of derailments or oil spills in this state: build an oil pipeline. (The state already has some fuel pipelines, but not one that's state-wide.)

Railroad industry experts are questioning the early explanation from Union Pacific for why its oil train crashed in Mosier, Ore.

Union Pacific said the preliminary indications from its investigation are “the failure of a fastener that connects the rail to the railroad tie,” according Justin Jacobs, a railroad spokesman.