RIO DE JANEIRO, Feb. 27 (Xinhua) -- Two trains collided in Rio de Janeiro on Wednesday, killing one driver and injuring eight others, said local authorities.

The accident occurred when a train collided into the back of another that stopped at Sao Cristovao station near downtown Rio.

According to local transport authorities, most of the injured sustained only minor wounds, but the driver of a train was trapped in wreckage and some 30 firefighters worked for seven hours to free him. Unfortunately, he suffered cardiac arrest and was pronounced dead after failed efforts at resuscitation.

Of the eight people injured, only one remains in hospital while the others were treated and released.

Rio train operator SuperVia said it will investigate the causes of the accident.

Local transport regulation agency Agetransp, which is in charge of monitoring all transport concessions in Rio, also said it will carry out a full investigation.