Allentown is marking the first anniversary of a gas explosion that killed five people.

While the city has dealt with explosions before, technology brought the blast at 13th and Allen streets closer to home for many emergency workers.

When the explosion happened, 911 operators had a front row seat to the rescue effort.

"When you see every one of your 911 lines light up at the same time, you can pretty much guarantee there is a significant event," said Michael Hilbert, a communications center superintendent.

February 9, 2011, was an event that emergency dispatchers in Allentown had literally never seen before, but recently installed crime cameras put them at the scene of the explosion.

"What the camera operator saw when he panned the camera to look east on Allen Street was sheer devastation," Hilbert said. "There was fire. There was fire in the street. There was debris in the street. We had a hard time telling where the devastation even ended, how many houses were even involved."

For the first time, dispatchers were able to watch the disaster and its aftermath unfold -- firefighters battling the blaze, residents watching in awe and the silent search through the charred rubble.

"When they called for the coroner, we knew what was going on at the scene," Hilbert said.

It was the job of dispatchers to capture every aspect of the explosion on camera, knowing they would be watching the removal of five bodies, including an infant.

"Some people, I think, dealt with it better than others," Hilbert said. "Some people could look at it. Some chose not to."

It was a heart-breaking, real-life training experience dispatchers hope they will never have to repeat.

"It showed us video capability of cameras for use for video evidence," said Hilbert. "As you know, the PUC is using this video. It undoubtedly will be utilized in the civil suits that are coming. It opens up a whole new realm of our responsibility to document as best we can what's out there."

The crime camera video will be utilized in legal actions now under way.

A wrongful death suit has been filed against Reading-based UGI, and several of the homeowners who lost everything are also seeking compensation.

This weekend, 69 News will premiere a documentary on the explosion and its aftermath.

The half-hour special, "Time Bomb: Allentown Gas Explosion," will air this Saturday at 7:30 p.m. on WFMZ-TV.