The Chinese people are in mourning after two high-speed trains collided in Wenzhou on Saturday, killing 39 of their countrymen.

Wen Jiabao, the country's Premier, visited the site of the accident Wednesday, speaking about his grave sadness and vowing to discover every detail of what happened Saturday night. The crash was China's worst train accident since 2008; more than 200 people were injured.

"No matter if it was a mechanical fault, a management problem, or a manufacturing problem, we must get to the bottom of this," Wen said.

"If corruption was found behind this, we must handle it according to law and will not be soft. Only in this way can we be fair to those who have died."

A Chinese railway research group -- called The Beijing National Railway Research and Design Institute of Signals and Communications Co. Ltd. -- admitted blame and issued an apology to the people of China. The company said a signal failure on the track allowed one train to proceed while a second train was stalled on the track ahead.

The railway institute said it will "face up to shouldering responsibility, and accept any punishment that is due, and will strictly undertake pursuing culpability of those responsible", news agency Xinhua reported, citing a statement.

"Safety overrides all else, and high-speed rail safety is of even more overriding importance."

"Without safety, high-speed trains will lose their credibility," Wen agreed. "This deadly accident has reminded us to attach more importance to the safety of our high-speed railways."