Tampa police announced Wednesday that they had charged a 17-year-old expelled student with planning to blow up Freedom High School on the first day of class.

Tampa Police Chief Janet Castor said the plot was “a potential catastrophic event the likes of which this city has never seen.”

In a manifesto recovered by police, the former student described potential targets and “his desire to cause more casualties than were suffered at Columbine,” Castor added.

The suspect was identified as Jared Cano. Officials said that bomb-making materials and a marijuana growing operation were found in his apartment.

He had previously been charged with burglary, carrying a concealed firearm and marijuana possession.

A Tuesday morning message on his Facebook page said, “i just did the dumbest thing ever!”

Watch this video from CNN’s Newsroom, broadcast Aug. 17, 2011.