Yolo County officials said Thursday that the investigation and recovery efforts could take days, and said their hearts and thoughts are with the families of the 7 people who are missing.

Among those waiting in anguish is Jhonny Ramos. His 18-year-old son Jesus and 22-year-old son Johnny are still missing. Speaking in Spanish, Ramos said there couldn’t be a more “cruel death” and believes their bodies may still be buried in the rubble.

As fireworks crackled in the night sky and flames flickered from a warehouse explosion in Yolo County, a mother cried out the names of her three missing sons.