A rush-hour commuter train sped through a red signal and slammed into an oncoming train as it left a suburban Brussels station Monday, killing at least 18 people and disrupting rail traffic in northern Europe.
Investigations into one the worst accidents on the Belgian rails were likely to focus on whether human error was responsible or if it could have been influenced by the persistently freezing temperatures that have iced up the European capital.
Officials said 80 people were injured, 20 of them seriously, and the death toll - 15 men and three women - was not considered final. As darkness fell more than 10 hours later, rescuers were still looking for victims in the wreckage, said Jos Colpin, the spokesman for the federal prosecutor's office.
CBS News correspondent Mark Phillips reports that emergency medical workers set up a triage and command center near the scene of the accident to coordinate their effort. People were still thought to be trapped inside the trains several hours after the crash.
The fate of the two drivers was not immediately known, and officials said they were having difficulty identifying some of the victims.
The trains, carrying a total of about 300 passengers, collided in light snow just outside of the station at Buizingen about 9 miles (15 kms) from Brussels around 8:30 a.m. (0730 GMT).
The impact peeled away the front of one train car and threw at least one other off the tracks, severing the limbs of some passengers, witnesses and officials said. One engine was thrust high into the air and snapped overhead power lines.
"When we came out we saw dead bodies lying next to the tracks, some mutilated," said Patricia Lallemand, 40, who was in a middle car of one train and was unhurt.
Lodewijk De Witte, the governor of the province of Flemish Brabant, told reporters one train "apparently did not heed a stop light."
One of the front cars appeared to have careened across the tracks, demolishing a small maintenance shed next to the rail line. A high concrete wall around the train yard seemed to have kept debris from hitting nearby houses.
Herman van Rompuy, president of the European Council, expressed his "shock and sorrow" over the accident. King Baudouin and Prime Minister Leterme, who canceled a trip to Kosovo moments after landing in Pristina, visited the crash site.
It was the first serious Belgian train accident since March 28, 2001, when eight people died when a crowded train plowed into an empty train driving on the wrong tracks. The worst European crash in recent history was near the German town of Eschede in 1998 when around 100 people were killed when a cracked wheel hurled a train off the tracks.
Belgian National Railways spokesman Jochen Goovaerts said his agency was awaiting the outcome of the investigation before discussing the cause of Monday's accident.
Eurostar canceled its service from London to Brussels for Monday and advised passengers the line was likely to remain closed Tuesday. The high-speed Thalys train suspended dozens of trains from Paris to the Netherlands and Germany for two days.
At least four Thalys trains were stopped en route, and the railway operator deployed staffers to stations where they were rerouted to provide assistance to travelers on board, said spokeswoman Patricia Baars.
"It was a nightmare," Christian Wampach, 47, told The Associated Press after medical workers bandaged his head at a sports complex where the less seriously injured were treated. Badly hurt victims were taken to 14 hospitals in the Brussels area, and the Red Cross appealed for blood donations.
"We were thrown about for about 15 seconds. There were a number of people injured in my car, but I think all the dead were in the first car," said Wampach, who was in the third car of a Brussels-bound train.
Wira Leire, 20, said he was woken by a loud crashing sound and leapt to his bedroom window to see two cars jackknifed directly in front of his home.
"There were people lying on the ground next to the train, so I grabbed some blankets and ran into the back garden," he said. "But I but couldn't climb over the concrete wall, so I just threw the blankets to the rescuers who were already gathering."