The clouds that had hung above the Cathedral of Learning throughout the day burst during… The clouds that had hung above the Cathedral of Learning throughout the day burst during setup, but Pitt Program Council’s annual Laser and Fireworks Extravaganza continued despite the weather.

“The rain won’t stop us,” said David DeSafey, the Zambelli International Fireworks Manufacturers employee who ran the 20-minute fireworks display. “We could shoot right through it.”

The show began at 9 p.m. Friday, with fireworks from the fifth, 10th, 25th and 40th floors of the Cathedral and from nearby Mazeroski Field. A computer system called Fireone controlled the launching of the fireworks.

“The entire display is computerized,” DeSafey said.

It’s standard for fireworks displays this large to be choreographed and directed entirely by computer programs, DeSafey said.

“Years ago shells were shot one at a time,” DeSafey said. “Now, it has to be fast and rapid to keep peoples’ attention.”

The display featured hearts, strobes, chrysanthemums and serpents of various shapes and colors, all set to music included in the computerized program.

“You’ll certainly hear a lot of boom,” DeSafey predicted a few hours before the show.

Setup for the display took two days, and cleaning continued into the weekend. In addition to DeSafey and his crew, firemen were placed around the Cathedral in accordance with safety regulations.

The display, which was followed by a festival featuring arcade games, balloon art, body art and tarot readings in the William Pitt Union, was uninterrupted by rain. Each shell, DeSafey explained, is named, numbered and timed, and the show went on as planned.

“Each shell is precisely programmed,” DeSafey said. “We’ve got it down to a science.”