Emergency workers and Amtrak personnel inspect a derailed Amtrak train in Philadelphia, Pennsylvania, on Wednesday. The train's passenger engineer was identified as Brandon Bostian, a 32-year-old who lives in Queens, New York. Reuters

Brandon Bostian, the passenger engineer controlling Amtrak Train 188 when it derailed Tuesday, was a staunch defender of railway safety rules. For years, Bostian, 32, participated in online forums that revealed his fascination with train operations and his aspiration to work the rails.

Bostian seemed to be an active user on Trainorders.com, a website for "hungry railroad enthusiasts," according to the website's about page. A user named "bwb6df" who signed his posts as "Brandon Bostian" joined in dozens of conversations between 2003 and 2014. His profile lists his interests as Amtrak and commuter rail operations.

In one thread from 2009, Bostian weighed in on a debate about whether an overworked engineer should stop the train to get a new crew when his or her hours are up. The top post asked if there was a better system that didn't involve forcing passengers to wait, but Bostian seemed to stand by the rules.

"Everyone wants an extension to hours of service to avoid inconvenience, but what will you say when the crew that's been on duty for longer than 12 hours accidentally falls asleep and passes a stop signal and rear-ends a loaded hazmat train, killing dozens or hundreds of people?" Bostian wrote. "A crew is probably not any less safe after 12 hours and one minute than they were a few moments ago, but you have to draw that line somewhere."

In a similar thread, Bostian wrote that violating hours of service was too risky because they could "slip up and cause loss of life due to poor judgement [sic]."

The site's owner, Todd Clark, wrote in a notice Wednesday that he'd received multiple requests from members to take down Bostian's posts but "it would not make a difference" because Google had archived them. "I would like to add that I encourage our visitors not to reach a judgement [sic] until all the facts are in," Clark wrote.

Bostian's posts include his opinions on reduced fares, dining plans, radio tones, vintage subway trains, finances of short lines, and trespasser fatalities. He asked the forum's members how he should get started with a railroad-related career and what his chances were of being hired based on his experience. He used technical terms and often referenced how companies can make passengers safer.

Bostian became a passenger engineer with Amtrak in December 2010, after spending more than four years as a passenger conductor there, according to his LinkedIn profile. Before that, he was a cashier at Target in Columbia, Missouri, where he studied business at the University of Missouri. He graduated in 2006 and now lives in Forest Hills in Queens, New York. "He told me he liked Amtrak," his neighbor Moresh Koya told the NY Daily News. "He was happy working there, nothing negative. He was happy with his job."

In recent years, Bostian also campaigned for marriage equality. A 2012 article from the Midtown Gazette mentions Bostian's attendance at a panel at the LGBT Community Center in Manhattan. He had recently come from San Francisco, where he fought Proposition 8, which would only allow marriage between a man and a woman. “It’s kind of insulting to have to beg people for my right to marry,” Bostian said at the time. “I feel like we shouldn’t even have to have this fight.”

On Tuesday night, Bostian was in command of Train 188 when it entered a curve with a 50-mph speed limit going 106 mph, National Transportation Safety Board member Robert Sumwalt told reporters. It derailed, injuring more than 50 and killing at least eight people. Bostian was among the wounded -- he went to the hospital, where he received 14 staples in his head and was treated for a knee injury, attorney Robert Goggin told NBC News. He talked to police and gave a blood sample after his discharge.

"He remembers driving the train, he remembers going to that area generally, has absolutely no recollection of the incident or anything unusual," Goggin said. "The next thing he recalls is being thrown around, coming to, finding his bag, getting his cell phone and dialing 911."

Transportation safety board member Sumwalt told the Today show that investigations revealed that the engineer applied the brakes on Tuesday, and the agency planned to question Bostian soon. "We want to understand what was going on," Sumwalt added. "We want to understand why the train was operated that way. Was it a mechanical issue? Was it some sort of human issue? That's what we're here to do."

Amtrak and Goggin did not return requests for comment Thursday.