SZCZECHOCINY, Poland (AP) -- Two trains running on the same track collided head-on in southern Poland in a shower of sparks, killing 16 people and injuring 58 in the country's worst train disaster in more than 20 years.
The crash near Krakow turned cars at the front of each train into heaps of mangled metal and toppled others on their sides. Neighbors in the town of Szczechociny alerted by what they said sounded like a bomb rushed to the scene to smash open windows, and survivors emerged in a state of shock, many crying out for help and carrying baggage.
Rescuers worked through the night to recover bodies and help the wounded.
One of the trains was on the wrogn track. Maintenance work was being done on the tracks before the accident, but officials said it's too early to determine the cause of the disaster.
A woman living in a house about 200 meters (yards) from the site of the accident said she was standing at her window when the two trains collided, creating a "terrible, terrible noise -- like a bomb going off."
"So I ran out of the house, and on one side I saw train lights and one the other side I saw train lights, and in the middle sparks," Anna Sap said. "People from the train starting crying, 'Help, help!' So we and the neighbors ran to them. Some of them smashed windows to let them out."
Her husband Grzegorz Sap added that people began emerging from the train "with hand luggage and in shock. They had no idea where they were."
An unnamed passenger interviewed on the all-news station TVN24 said he felt the force of the collision.
"I hit the person in front of me. The lights went out. Everything flew," he said. "We flew over the compartment like bags. We could hear screams. We prayed."
The U.S. consulate in Krakow said an American woman was among the dead and her family had been informed. Spokesman Benjamin Ousley said he could give no more information and that Polish authorities would release further details at a later point.
Prime Minister Donald Tusk earlier had said that several of the passengers were foreigners, including people from Ukraine, Spain and France, but none of them were among the dead or mostly seriously injured.
President Bronislaw Komorowski visited the site Sunday, saying that when rescue efforts are over he would make an announcement about a period of national mourning.
"This is our most tragic train disaster in many, many years," Tusk said.
Rescuers brought in heavy equipment to free a body from the wreckage, and ended up finding two, a man and a woman, said Krzysztof Dobrzyniewicz, the mayor of Szczechociny.
Rafal Krupa, a council member in the nearby town of Zawiercie, said emergency workers got to the site as quickly as possible but that in the first moments it was difficult for them to determine where the crash had occurred. Passengers on the train "began calling in to the emergency services but they weren't really aware of where they were," he said.
A doctor in one of the hospitals, Szymon Nowak, said many of the injured were in a serious condition, with some in artificially induced comas.
"It's a very, very sad day and night in the history of Polish railways and for all of us," Tusk said.
The trains could hold up to 350 people but it's not clear how many were actually on board.
The accident comes three months before millions of soccer fans will start crisscrossing the country -- many by train -- to watch matches at the Euro 2012 championships, which is being co-hosted by Ukraine.
Poland, which is still recovering economically from decades of communist rule, doesn't yet have the high-speed trains of Western Europe -- many of the local trains are old and slow. However, the country does offer fairly speedy service between some key cities, and trains are generally seen as safe and used by many in the country of 38 million.
Prosecutors have opened an investigation into how the train was on the wrong track, but officials said it was too soon to draw any conclusions.
One train was traveling from the eastern city of Przemysl to Warsaw in the north, while the other -- on the wrong track -- was heading south from Warsaw to Krakow.
Komorowski visited the crash site Sunday, as well as hospitals where the injured were being treated.
"The scale of this phenomenon is so large that there should be nationwide mourning," he said.
In Germany, Foreign Minister Guido Westerwelle expressed his nation's condolences to the victims' families and wished the injured a swift recovery.
"It is with horror that I learned about the grave train accident in Poland that killed numerous people and injured many others," Westerwelle said. "Our deepest compassion and our condolences go to our Polish friends."
The tragedy was Poland's worst involving trains since 1990, when 16 people were killed in a collision involving two trains in the Warsaw suburb of Ursus. Since then, the most serious Polish rail accident was in 1997, when 12 people were killed in Reptowo.
The country's most deadly train disaster post-World War II dates back to 1980, when 65 people were killed when a freight train collided with a passenger train near Otloczyn.
Associated Press writers Vanessa Gera in Warsaw and Juergen Baetz in Berlin contributed to this report.