Newly released video footage taken by a security camera shows the huge explosion last Thursday at an industrial estate in Arganda del Rey, some 30 kilometers southeast of Madrid.
Up to 18 firetrucks were sent to the blaze. Seconds after the first explosion there was a second that could be heard up to 20 kilometers away, creating a conflagration within the warehouse, catching several employees and emergency workers unaware: 35 people were injured, three of them seriously.
The waste management plant specialized in treating solvents.
Three people sustained burns to more than 30% of their bodies and were rushed to nearby hospitals, where they remain in a serious condition. Other people were treated for cuts and for smoke inhalation injuries.
The fire sent a huge plume of black smoke hundreds of meters into the air and schools in the area were evacuated. It took firefighters 24 hours to finally put out the blaze.
English version by Susana Urra.