Today I want to share with you some of the most heartbreaking testimony I've ever heard in a courtroom.

This comes from the sentencing hearing for Matthew Devlin, the tug boat operator who pled guilty in the Delaware River Duck Boat accident that killed two teenagers.

The story is tragic beyond words.

Devlin had a spotless safety record and was pushing a 250-foot barge on a routine trip up the Delaware on a clear day. But because a Duck Boat employee failed to secure a pressure cap, the boat's engine overheated in the middle of the Delaware. The operator mistook the rising steam as smoke from a fire and shut the boat down. He anchored the vessel and waited for help.

Meanwhile, hundreds of miles away in central New York state, the son of the tug boat operator was suffering complications from what was supposed to be routine eye surgery.

Devlin's wife, Corinne, called her husband's cell phone to report the problem. Devlin spent much of the next hour in a panic, fearing his son might have suffered brain damage.

He made cell phone calls, searched for medical information on a computer, and most critically, moved from the tug's upper wheelhouse, where he had a commanding view of the river in front of the barge, to the tug's lower wheelhouse, where visibility was sharply limited.

In the video above, you can see the barge glide inexorably toward the stranded sightseeing vessel.

Devlin never saw the Duck Boat until he'd pushed the barge over it, spilling dozens of people into the water. He'd turned down radios that were blaring warnings from others on the river.

You can read the National Transportation Safety Board's report on the accident here.

Devlin pled guilty to the maritime equivalent of involuntary manslaughter, and at the sentencing hearing Corinne Devlin took the stand to describe what happened with their son Jacob's surgery.

Assistant U.S. Attorney Robert Zauzmer (the same guy who prosecuted Vince Fumo) said prosecutors actually traveled to New York State and interviewed the doctors and others involved with the operation, and verified Corinne's account.

Jacob Devlin recovered fully, and one of the lessons of the episode is that medical staff need to speak to parents in such a circumstance with far greater care and sensitivity. You have to wonder if a little more information and reassurance for this distraught and confused mother might have changed the outcome.

Zauzmer said in court prosecutors have great sympathy for Matthew Devlin, but that his actions that day were so negligent that some punishment was appropriate. Devlin received a year and a day in prison.

Prosecutors also showed a video of the families of the two Hungarian teenagers who died in the accident, which you can watch below. Both teenagers were only children.

The audio above is part of the court testimony of Corinne Devlin, who explains what happened that day, and why she's tormented with guilt over her phone call to her husband.

Relatives the dead teenagers were listening by speaker phone.