By Ruma Paul DHAKA (Reuters) -Firefighters worked for a second day on Sunday to extinguish a massive blaze that killed at least 49 people at a container depot in southeast Bangladesh, the latest incident highlighting the country’s poor industrial safety track record. The fire that also injured more than 200 broke out at the shipping container facility on Saturday night at Sitakunda, 40 km (25 miles) from the port city of Chittagong, triggering a huge blast and multiple container explosions, officials said. Chemical-filled containers were still exploding on Sunday as firefighters attempted to d…