The bells of Ste-Agnes church will chime 50 times, followed by a minute of silence at noon.
"Think of the people who are enduring this, who are in mourning," said Jean-Denis Martel, as he sat in the church on Friday, his voice choked with emotion.
"It's good to take a moment of silence, for those with loved ones. It's not easy. It hurts bad."
The tribute follows one Friday night in which people gathered for a candlelight vigil as darkness settled over the town.
They stood in small clusters, whispering to each other or hugging on the steps of the church. Some arrived with small children in strollers.
"In one way or another, we're all affected," said Bianca Fillion.
But the vigil offered some solace.
"We can feel the love," said Cynthia Jacques.
Another group walked solemnly through Old Montreal before stopping in front of historic Notre-Dame Basilica where they erected a small shrine.
A visibly moved Richard Lafontaine said he had to show support for the people in Lac-Megantic.
"Solidarity," he said. "We're participating in a movement of solidarity for the region and especially the town."
Vigils were held in other Quebec communities including Sherbrooke, Quebec City, Trois-Rivieres and Gatineau as well as cities outside the province such as Winnipeg.
The Lac-Megantic vigil had initially been cancelled because the community is still under a state of emergency. Quebec provincial police, who are busy combing through the obliterated downtown in search of bodies, said they couldn't spare the resources to handle a large crowd.
But that didn't stop heartsick townsfolk from gathering to share their grief and light candles in memory of missing and dead loved ones.
The tributes are only just beginning.
Quebecers are also being urged to attend at least three benefit concerts scheduled for next week. Events are planned in Montreal, Quebec City and St-Georges-de-Beauce. Players from the Montreal Canadiens and Philadelphia Flyers are among those contributing items for charity auctions for Lac-Megantic.
When the clock struck 1:14 a.m. on Saturday, it marked one week to the minute when an out-of-control caravan of rail tanker cars came rumbling into the town, jumped the tracks and exploded into searing balls of flame.
The Montreal, Maine and Atlantic Inc. train had been parked for the night a few kilometres away on a steep grade. The engineer had left it unattended to get some shuteye.
The explosion and fire triggered by the derailment incinerated much of Lac-Megantic's downtown, which was dotted with historic buildings, homes and commercial outlets.
About 1,800 people had to flee the area but most were able to return as the week progressed.
Along with grief there is also a lot of anger at the railway as townsfolk struggle to cope with their terrible losses. An appearance by railway chairman Ed Burkhardt at an impromptu news conference earlier in the week sparked outrage and Burkhardt was reportedly advised to scrap plans to address a town meeting.
Officials have confirmed 28 deaths so far and have been able to identify eight of the victims. However, another 22 people remain missing and are also feared to have perished.
Provincial police, backed up by the RCMP, have cordoned off a swath of the town to facilitate the recovery effort and the investigation of what has been declared a crime scene.
Police have already arrested one trespasser and on Friday warned people not to climb fences erected around the area or try to get a look at the devastated area from surrounding rooftops.
Insp. Michel Forget said several people had been spotted doing that and he warned of the danger of such behaviour.
"We don't want any more victims," he said.
The federal Transportation Safety Board said its investigation into the derailment will likely take months.
"This may well be the most devastating rail accident in Canadian history," board chairwoman Wendy Tadros told a news conference.
Elsewhere, the chairman of the House of Commons transportation committee said a push for parliamentarians to meet this summer to assess railway safety is more about partisan politics than Quebec's catastrophe.
Conservative Larry Miller made the remarks from his riding in Owen Sound, Ont., in response to calls by the NDP and Bloc Quebecois to convene hearings next month.
"There has to be something concrete that we can actually do or it's just a waste of everybody's time," he said.
(With files from Nelson Wyatt and Jerome Roy in Montreal and Patrice Bergeron and Melanie Marquis in Lac-Megantic)