¡¡¡¡ROME, Oct. 1 (Xinhuanet) -- Italian Turin prosecutors opened Wednesday an investigation into the blackout which struck Italy inthe early hours of Sunday morning as grid operators continued to argue over responsibility.

¡¡¡¡Although the outage is believed to have begun in Switzerland, the nationwide cut occurred after a key energy distribution plant near Turin was unable to cope with the consequent surge in demand. ¡¡¡¡

¡¡¡¡The northern investigators will be working with counterparts in Rome, who on Tuesday opened an inquiry into the events preceding the outage, to determine the causes of the blackout, possible knock-on effects and legal responsibility.

¡¡¡¡Rome prosecutors have tasked judicial police with acquiring documents from the national grid company GRTN and meeting with its technicians and directors, while the Turin inquiry will focus on the Rondissone station, which is a conduit for two very high-voltage power lines from France.

¡¡¡¡The Italian government and national Energy Authority have launched their own investigations into what happened.

¡¡¡¡Meanwhile, in its first official statement after Sunday's events, GRTN on Wednesday blamed Swiss suppliers for aggravating the situation following the initial breakdown.

¡¡¡¡"Communications center Etrans, which coordinates the six Swiss electricity operators, failed to inform us of what had happened promptly or adopt the agreed emergency procedures," it said.

¡¡¡¡"This lack of information ... prevented a swift identification of the causes and blocked the adoption of necessary countermeasures".

¡¡¡¡Italy's blackout, its worst ever, began shortly before 3:30 on Sunday morning, plunging all regions except the island of Sardiniain to darkness for hours on end.

¡¡¡¡At least four deaths were indirectly attributed to the blackout,including two elderly women who fell down stairs and another whose clothes were set on fire by a candle.

¡¡¡¡Another person died in a car accident caused by traffic light failure.

¡¡¡¡On Wednesday, four top consumers associations launched a campaign encouraging the public to request compensation for the blackout.

¡¡¡¡Adoc, Adusbef, Codacons and Federconsumatori noted that customers are legally entitled to 25.82 euros for lengthy power cuts. Enditem