One person was killed and a dozen injured in an explosion Tuesday at a British-owned weapons factory outside Rome.
The victim was identified as Roberto Pignalberi, 32, father of an infant child.
The blast occurred when workers were pouring a highly inflammable potassium-based liquid compound into a container.
Explosives experts said they did not know what ignited the mixture.
Twelve people were injured in the blast.
Ten are being "monitored" in the ER room of the local hospital where Pignalberi died of severe head injuries shortly after his arrival, doctors said. One was admitted to hospital, suffering from burns to a foot.
Another patient, suffering from severe burns to the arms and face as well as multiple fractures, was taken by helicopter to a Rome hospital where his condition was described as serious but not life-threatening.
The blast took place in the plant's heavy explosives sector. There were some 25 workers there at the time.
The plant at Colleferro, some 40km (25 miles) southeast of Rome, belongs to Simmel Difesa, which manufactures ammunitions, explosives, missile warheads and rockets for the armed forces in Italy and abroad.
Founded in 1948, Simmel is Italy's only manufacturer of heavy munitions.
For several years it was at the centre of protests against cluster bombs. It recently withdrew the controversial weapons from its catalogue.
Simmel, which employs 200 people and has an annual turnover of some 80 million euros, became part of the Fiat group in 1988.
It was bought by British defence company Chemring Group last March.
