Rail advocates had expected to celebrate a breakthrough Monday for the Northwest passenger rail system, a $181 million bypass that would shave time off the Portland-Seattle loop, allowing trains to run at higher speeds and squeeze in more trips each day.

Instead, the inaugural passenger train on the Point Defiance Bypass jumped the tracks, spilling cars from a freeway overpass onto Interstate 5 below. At least three people were killed and dozens injured.

The much-anticipated route was intended to cut 10 minutes off the stretch between Tacoma and Olympia by running alongside I-5 instead of hugging the Puget Sound. It also had fewer curves - limiting the need to slow down - and single-track tunnels where passenger trains must yield to passing freight trains.

It was part of Washington's strategy to make rail more competitive with driving and flying, said Lloyd Flem, the executive director of the advocacy group All Aboard Washington. "It's beginning to work," he said. "It's not just discretionary; you're starting to see business travel."

Flem said he worried Monday's tragedy might curtail that success, though he pointed out that rail travel is statistically safer on a per-mile basis than traveling by car.

"This is a terrible set back and a tragedy," he said, noting he was still waiting to hear from some of his group's members who'd been on board. "But we're certainly going to continue to push the idea that trains are a good investment after the dust is totally settled."

The $181 million endeavor was largely funded as part of the 2009 federal economic stimulus. Work on the bypass began in 2014.

But the plan to run more trains at higher speeds through population centers was never without controversy, or safety concerns: The city of Lakewood, five miles from the crash site, sued the state in 2013 in a bid to halt the project. Mayor Don Anderson said the number of street level crossings and the route's higher speed limit presented a collision risk.

Monday's crash occurred near an interstate overpass, not near a street-level crossing.

But it's not clear what role speed played. Most of the 19.5-mile route had a higher speed limit of 79 mph, but trains were supposed to slow to 30 mph near the derailment site, just south of DuPont.

Amtrak President Richard Anderson told reporters that positive train control -- technology that automatically slows trains to posted speed limits -- was not activated at the time of the crash. The technology is scheduled to be broadly implanted by federal mandate before the end of 2018.

The Associated Press reported the train might have hit an obstruction on the track, citing an unnamed official. The National Transportation Safety Board has investigators on scene, and it may take days or weeks before they issue a finding.

Amtrak officials said there had been numerous test runs of trains on the new tracks in the weeks leading up to the new route opening.

Oregon had looked to Washington state's rail expansions to guide its own lagging efforts.

Washington state had $800 million worth of plans ready when federal stimulus funds became available. Oregon didn't have a plan ready, said Kitty Piercy, a former legislator and mayor of Eugene who served on the state's Passenger Rail Leadership Council. It's since identified projects to improve passenger rail traffic but hasn't identified funding.

"Here in Oregon, we have always been grateful that Washington has been so progressive in trying to improve its part of the corridor," Piercy said. "We would all be concerned that nothing happens to undermine the viability of this particular form of public transportation."

Rail advocates from the Association of Oregon Rail and Transit Advocates had gathered Monday at Union Station in Portland to greet Train 501 when it arrived from Seattle. Instead, they learned it had derailed during the trip.

Donald Leap, the group's government affairs director, said he was confident the incident wouldn't have a long-term effect on ridership.

"This was really going to be a milestone because of its improved ability to serve a business customer," said Donald Leap, the group's government affairs director. "This is a sad, sad moment."

-- Elliot Njus

enjus@oregonian.com

503-294-5034

@enjus

Fedor Zarkhin contributed to this report.