A blast so powerful that it ripped away bricks from a Detroit apartment building and injured a dozen people, including six children, is under investigation early Monday, as demolition crews try to stabilize the structure.

Three of those injured were in the same apartment and suffered critical burns. According to Fox 2 in Detroit, a 30-year-old man with burns on 90% of his body, a 27-year-old woman with burns to 20-40% of her body, and a 3-year-old girl with burns to 15% of her body were among the most serious.