Sen. Maria Cantwell has sent a letter requesting a congressional inquiry into Amtrak safety procedures in light of the Monday derailment in Washington state that killed three people and injured dozens more.

After Monday’s crash, at least 22 people have died as a result of Amtrak derailments and crashes since 2011. The train system has averaged roughly two derailments per month in recent years, Federal Railroad Administration statistics show.

“Millions of Americans depend on rail service each day, and businesses in every corner of our country depend on freight rail to keep commerce running,” Cantwell, a Washington Democrat, wrote in the letter to the Senate Commerce, Science and Transportation Committee, the Seattle Times reported.

“The alarming rate of incidents on our rails is cause for tremendous concern,” she wrote.

Cantwell and 14 other senators, including fellow Washington Democrat Patty Murray and Oregon Democrat Jeff Merkley, previously signed a letter to Transportation Secretary Elaine Chao requesting that she hold rail service companies accountable for neglecting safety precautions.

The train that crashed Monday in Dupont, Washington, traveling from Seattle to Portland, was roaring at 80 miles per hour, more than 50 miles per hour over the speed limit, as it approached the bend where it derailed.

The signatories requested a report on the effectiveness of a satellite-tracked safety system called positive train control, or PTC, that can remotely slow a train’s speed as it approaches bends or obstacles.

Some experts have said PTC could have prevented Monday’s derailment.

The hearings on Amtrak safety should include testimony not just on PTC and other technological concerns but also on logistical issues such as crew training, staff levels and proper routing, the senators wrote.

Transportation Committee Chairman John Thune signaled Friday he is eager to work with his colleagues to hold hearings and improve train safety.

The South Dakota Republican “is already planning an early 2018 hearing on positive train control implementation,” a spokeswoman said in a statement Friday.

“The Chairman appreciates Senator Cantwell’s commitment to rail safety.”

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