The train, which had two locomotives and 80 loaded coals cars, was traveling from West Virginia to Baltimore. According to reports, 21 cars derailed, including some onto a nearby parking lot.
The derailment shut down Ellicott City's Main Street starting at Old Columbia Pike. Pedestrians could walk almost all the way down to Maryland Avenue, however, and the accident attracted a crowd of onlookers, including some public officials.
The National Transportation Safety Board had taken over the investigation, and Jim Southworth, investigator in charge or the incident, spoke to the media Tuesday afternoon.
Southworth said he and his nine-member team spent the day gathering as much information as possible: video from a camera mounted to the front of the train, which will be sent to Washington for examination, as well as photos of the tracks and witness statements.
Three crew members were on the train, Southworth said, and "felt nothing and saw nothing" until the emergency brake was activated.
The brake, Southworth said, is activated any time there is a disruption — like a derailment — along the line of cars. Southworth would not say what caused the derailment, nor did he know where the break was in the line that caused the brake to be pulled. The train, he said, was traveling at 25 mph, and the cars that derailed were immediately behind the front locomotive.
"These accidents happen very quickly, in a matter of seconds," Southworth said. "And the investigations are quite lengthy, and that's on purpose. (We're leaving) no stone unturned. We want to know not just what happened, but why it happened."
County Council member Courtney Watson, a Democrat who represents Ellicott City, said she was given a tour of the accident scene.
"It's hard to imagine until you see it," she said. "It's car after car after car overturned."
Watson added: "They're working as fast as they can to get it open."
County Executive Ken Ulman had arrived at the scene shortly after the derailment early Tuesday morning and had stayed through early morning, she said.
In a statement released Tuesday afternoon, Ulman called the derailment "a terrible tragedy" and extended sympathies to the victims' families.
"Within an hour of the incident, I was on the ground to witness the swift and coordinated response efforts of our public safety personnel — from both Howard and Baltimore counties — as well as CSX and the National Transportation Safety Board," Ulman said in the statement. "I want to thank our local and federal partners for their support as the investigation continues, and ask that the community continues to keep the Nass and Mayr families and friends in our thoughts and prayers."
Some Main Street businesses opened as scheduled Tuesday. Others remained close through the late morning hours. Some business owners had not yet decided what to do.
Taylor's Antique Mall opened, but employee Susan Herd said: "We're not sure for how long."
Her colleague Noelle League said she felt really sad about the accident and noted: "It doesn't feel right to open."
The two had to open the store to do their scheduled payroll. They said they might close by midday, but as people started walking in they noted they may remain open just as a place for people to cool down from the heat.
Ed Williams, co-owner of Mumbles and Squeaks Toy Shoppe in Ellicott City, had just arrived at his shop shortly after 10 a.m. and said he hadn't decided whether to open.
"It's a tough call ... I don't think there would be any business," he said, noting he planned to stay downtown regardless of whether they open the shop.
Though the crowd of onlookers had already started to grow, Williams said: "I don't think it's appropriate to capitalize on a tragedy."