The [trucks] tank has four sections, and they were filling the first section when it happened, said Diane Brzycki, fire inspector for the Hammond Fire Department. Section three appears to be the one that blew. A worker said he had opened that section, but were trying to get the facts together. It certainly appears that there was a build-up of pressure.

The explosion blew off part of the roof of a three-story building. One IPC employee suffered second degree burns, while the driver of another truck that was parked nearby sustained blunt force trauma. Both remained hospitalized yesterday, Brzycki said.

IPC is based in Hammond and supplies automotive and industrial lubricants, along with viscosity index improvers and specialty chemicals.