CINCINNATI --

Firefighters said one person was injured in a chemical explosion on the University of Cincinnati campus.

The incident happened at about noon at the Engineering Research Center while a student was working with chemicals in a 6th floor lab.

Firefighters said there was an explosive reaction between two chemicals, which shattered the protective hood the student was behind.

"The glass in the fume hood broke when the chemicals reacted," said Jeff Corcoran, assistant chief of university police.

The student suffered cuts and abrasions, firefighters said, but his injuries were minor.

Officials said an alarm sounded to evacuate the building, but because it happened at the same time as Hamilton County's monthly tornado siren test, some people didn't leave the building immediately, thinking it was a drill.

Several hundred students were evacuated from the building and connecting buildings, and the engineering building remained closed Wednesday afternoon as workers cleaned up the damage.

Investigators are still trying to determine which chemicals caused the explosion.

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