Not building the Keystone XL pipeline and moving Canadian tar sands oil by rail could be far deadlier and more dangerous than previously thought, according to a list of corrections the U.S. State Department has released for its review of the controversial proposal to build the pipeline through the heart of America.

The State Department issued an errata sheet on Friday to update its Final Supplemental Environmental Impact Statement, which is thousands of pages long and was released Feb. 5.

The original analysis said companies would ship oil by rail if the pipeline isn’t built and concluded that would result in 700 injuries and 92 deaths over a decade. The Friday update said those figures should have been much higher, with 2,947 injuries and 434 fatalities.

The State Department blamed the mistake on an erroneous search used to gather information from the Federal Railroad Administration’s online safety data and statistics system. A State Department official said issuing an errata sheet is common practice and the corrections don’t change conclusions of the environmental impact statement or its integrity and are unlikely to influence any decisions.

The State Department was tasked with reviewing the Keystone XL as part of the application process for a permit Calgary-based TransCanada needs to build the pipeline across the Canada and U.S. border.

Officials have put a national interest review of the pipeline on hold indefinitely while awaiting the outcome of a lawsuit over the constitutionality of Nebraska’s major pipeline siting law being reviewed by the Nebraska Supreme Court. A decision in the case isn’t expected until well after the November midterm elections.

The proposed 36-inch-diameter pipeline would have the capacity to carry 830,000 barrels of oil a day and run 1,179 miles from Hardisty, Alberta, to Steele City in Southeast Nebraska, where it would meet up with an existing pipeline. Construction of that section of the pipeline is expected to cost $5.4 billion.

Jane Kleeb of Bold Nebraska criticized the State Department’s conclusions regarding the rate at which tar sands oil would be developed and shipped without the pipeline.

“No one, other than TransCanada and their front groups, think rail would replace the almost 1 million barrels of tar sands and benzene they would ship through the pipeline to the export market,” she said Tuesday. “There is simply no financial model that gives credence to this scenario.”

Environmental groups oppose developing oil sands at all. Bold Nebraska has sought to bring attention to the dangers of a leak in the sensitive Sandhills region or over the Ogallala Aquifer, which provides water for irrigation of fields and drinking for millions of people.

The Friday update also corrects the expected annual electric usage from pump stations for the pipeline, as well as addresses several typos and minor clarifications and additions to public comments.

TransCanada spokesman Shawn Howard said the update reaffirms that a pipeline is the safest and most economical way to transport oil to markets.

“Moving products we all rely on in the safest and most environmentally responsible manner should be in all our interest — and pipelines remain the best way to move products like oil to the refineries where they are needed,” he said in a news release.

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