Two former transport secretaries in Argentina received prison sentences on Tuesday for being responsible for a train crash in 2012 that killed 51 people, state news agency Telam reported.

A federal court sentenced Juan Pablo Schiavi to eight years and his predecessor Ricardo Jaime to six years for administrative mismanagement and for creating a public danger.

On Feb. 22, 2012, a packed commuter train crashed into station buffers in Buenos Aires, crushing the first three carriages and causing the country's third worst train tragedy. Another 789 people were injured in the incident.

In all, 21 of 28 people charged with crimes related to the crash were convicted and sentenced, most to jail terms of between eight and four years, the agency said.

Businessman Sergio Claudio Cirigliano, who operated the rail concession for the city, was convicted to nine years.

The court said the businessman and state officials bore greater responsibility than the train's driver, Marco Cordoba, who was sentenced to three and a half years.

The driver had said the train's brakes failed but technical evidence showed that other safety procedures were not carried out.

The trial, which began on March 18, 2014, saw 216 witnesses give testimony during 138 court sessions.

A photo of the courtroom showed relatives of the victims standing in the back, behind a glass partition, holding up photos of their loved ones as the sentences were announced.

"Justice has been done," Maria Lujan Rey, mother of one of the victims, Lucas Menghini, said after the court rulings.