Beirut explosion: What happened and who is responsible?

Beirut awoke to scenes of utter devestation this monring after two colossal explosions devastated parts of Lebanon's capital. They happened at a warehouse where nearly three thousand tonnes of highly explosive ammonium nitrate were being stored, apparently without any safety measures. At least 100 people were killed and 4,000 injured, according to the Red Cross. At the blast site in Beirut smoke continues to rise. The explosions shattered windows as far as 20 kilometres away. Rescue workers are continuing to look for survivors beneath the rubble. It's unclear how many people right now are missing. 

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