Two people have been killed in a workplace accident near Come by Chance, related to construction of a 230-kilovolt transmission line from Bay d'Espoir to the Western Avalon.

Work on the project has been halted and an investigation is ongoing, but CBC has learned the men were working on the tower when it collapsed.

Tragic day near Come By Chance. Two workers dead following collapse of tower like this 1. <a href="https://twitter.com/hashtag/cbcnl?src=hash">#cbcnl</a> <a href="https://t.co/KjEsf9gAYa">https://t.co/KjEsf9gAYa</a> <a href="https://t.co/NLv7JJpHhC">pic.twitter.com/NLv7JJpHhC</a> —@TRobertst

Newfoundland and Labrador Hydro has confirmed the fatalities.

Come by Chance fire Chief Duane Antle said his department got a call just before noon that there had been some sort of incident on the work site.

"By the time I got back to the town, my role was more of a support role," he told CBC News. "The emergency response had happened. From what I understand, it was a very tremendous effort by everybody involved and a lot of hard work done. Unfortunately, as you know, it didn't turn out the way that we hoped it would."

Traumatic event for many responders: fire chief

Antle said it was a difficult day for many of the responders, and there was a debriefing held after it was over to help them deal with what was for some a traumatic event.

"It's a piece of prevention work to ensure that the emergency responders who have seen difficult things, or had to do difficult jobs, are being looked after."

All construction on the transmission line has been halted effectively immediately," said a statement from NL Hydro earlier Monday afternoon.

It's the second deadly incident on transmission line work this year. In January, a worker was killed at a Maritime Link project site near Stephenville Crossing.

A statement from Hydro shortly before 6 p.m. said the workers were employed by a Hydro contractor, which it has not identified.

. <a href="https://twitter.com/NLHydro">@NLHydro</a> has not identified company involved in today's deadly incident near Come By Chance. But Forbes Bros. signs in area. <a href="https://twitter.com/hashtag/cbcnl?src=hash">#cbcnl</a> <a href="https://t.co/8UVIlDGbyL">pic.twitter.com/8UVIlDGbyL</a> —@TRobertst

"Hydro is working closely with the contractor with great concern and sympathy for the families and coworkers that have been affected by this tragic event," said the statement, which added that all details are not yet known.

"We will do everything necessary to support the contractor, their employees and all those working on the project. The safety of our employees, contractors and the public continues to be our number one priority," it said.