Two explosions ripped through a petroleum storage depot outside Moscow early Wednesday, killing two workers, injuring another and forcing the evacuation of hundreds of people from nearby homes and a hospital, emergency officials said. Preliminary investigations indicated that a technical problem sparked the explosions at the depot in the town of Noginsk, about 60 kilometers (35 miles) east of Moscow, said Sergei Vlasov, a spokesman for the Emergency Situations Ministry. The blasts ripped through a chemical laboratory at the depot at around 5:50 a.m. (0150 GMT), he said. Two tanks of petroleum products inside the lab then caught fire and the blaze spread to four nearby cargo rail cars that contained oil products. Two laboratory workers were killed and one was in critical condition, Vlasov said. Russian television broadcast footage showing firefighters spraying foam over a wide area of industrial equipment and thick black smoke rising from burning rail cars. Moscow regional prosecutor Ivan Sydorchuk said that the criminal investigation was focusing on safety violations and negligence. The fire had been contained by 9:30 a.m. (0530 GMT) but not before it had spread partially to a nearby maternity hospital, where nearly 200 patients and workers had to be evacuated, he said. More than 800 people from nearby apartments and a school were also evacuated, he said. Emergency workers dispatched a helicopter and a specially outfitted firefighting train to the scene, according to a report of The Associated Press.