Philadelphia (CNN) -- The sinking of a duck boat that killed two people was "another tragic example of the deadliness of distraction" the chairwoman of the National Transportation Safety Board said Tuesday after a final report showed several people involved were on the cell phones or computers.
The National Transportation Safety Board released its final report Tuesday for the duck boat crash last July in Philadelphia.
The collision killed two Hungarian tourists, Dora Schwendtner, 16, and Szabolcs Prem, 20, and plunged the amphibious vessel and its 35 passengers plus two crew members underwater.
The five-member safety board met to discuss the findings, probable cause and safety recommendations from the final report presented to the board by NTSB investigators.
The fatal collision between the duck boat and a barge on the Delaware River was "another tragic example of the deadliness of distraction," said Deborah Hersman, chairwoman of the NTSB.
According to NTSB findings, tugboat pilot, Matt Devlin, made and received 21 cell phone calls in addition to surfing the Web using a company laptop during his more than two hours at the wheel.
After the accident, Devlin initially told his superiors and the Coast Guard that he was dealing with a serious family medical emergency involving his 6-year-old son. Devlin refused to talk to investigators after those initial interviews.
The tug pilot was on an outbound personal cell phone call that lasted five to six minutes; investigators said at the time the duck boat operator was calling for help.
The deckhand on the disabled duck boat also was texting, and he sent several messages after dropping anchor, including one a minute before the barge hit.
The accident is not about the actions of one person, instead it is shedding light on a new and highly troubling societal norm, Hersman said.
"This is going to reach epidemic proportions," she said. "It is well past time to pay attention."
Devlin was in the tug's lower wheelhouse, not the upper wheelhouse as originally thought, leaving the stalled, 33-foot duck boat in his blind spot, investigators said.
The sightseeing duck boat was anchored in the shipping channel after being shut down because the boat's operator saw smoke and feared an on-board fire.
One of the final communications before the crash was from the operator of a passenger ferry moments before the two vessels collided: "Hey northbound barge. Northbound barge at Penn's Landing. That duck boat is broken down."
Ride the Ducks initially suspended its Philadelphia operation following the crash. Operations resumed in April with new safety procedures.
In addition to the two passengers who drowned, 10 other passengers suffered minor injuries, according to an NTSB report released several months after the incident.