Montreal has begun a controversial dump of 8bn litres (2.1bn gallons) of raw sewage into the St Lawrence River.
Officials in the Canadian city say that the project is necessary in order to replace old infrastructure in the sewage treatment system.
The operation has drawn the ire of people in Canada and in the US who have concerns that the river will be polluted with condoms and nappies.
The dump was delayed during the recent Canadian election.
Officials began releasing the raw sewage into the river just after midnight local time (05:00 GMT) on Wednesday, and say it could last about a week.
Citizens are being asked not to flush medication, condoms or tampons down the toilet while the operation goes on.
The diversion of the raw waste is needed so that workers can replace a snow chute - a large opening that funnels water from melting snow to a facility used to treat the sewage.
Officials at the city of Montreal have said the dump will have little effect on the fish population and will not affect the quality of drinking water for citizens.
Image copyrightReutersImage captionA sign reading "Don't touch the water" can be seen near the river
The plan was approved by Canada's new environment minister on the condition that a host of conditions including extensive monitoring were abided by.
However, the plan has drawn ire on both sides of the US-Canada border.
Mathieu Traversy, a provincial legislator of Parti Quebecois, said cities were concerned that riverbanks would be marred by "diapers, condoms and syringes".
Across the border, Senator Chuck Schumer of New York has asked the US Environmental Protection Agency (EPA) to intervene.
For its part, the EPA has said it has no regulatory authority over the river, which lies entirely in sovereign Canadian territory.
Media captionCol Michael Edmonson, of Louisiana state police, said footage of the incident was "the most disturbing thing I've seen"
Jeremy Mardis and his father, Chris Few, were in a car when they were shot in Marksville on Tuesday night.Two marshals in the US state of Louisiana are to be charged with murder after the fatal shooting of a six-year-old boy.
Officers Norris Greenhouse and Derrick Stafford were arrested after a vehicle chase that left Mr Few, who was driving, critically injured.
Jeremy died at the scene and Mr Few remains in hospital.
The two officers were arrested on Friday after body-camera footage taken from them was assessed.
It is still unclear what led them to pursue Mr Few and what triggered the shooting.
Image copyrightChris Few/FacebookImage captionJeremy Mardis was described as a delightful child "who loved everything, everybody"
Both were working secondary jobs in Marksville as marshals when the shooting happened, Col Michael Edmonson of Louisiana state police told a news conference.
"He [Jeremy Mardis] didn't deserve to die like that and that's what's important," Col Edmonson said.
Referring to the body-camera footage of the incident, Col Edmondson added: "I can tell you, it is the most disturbing thing I've seen, and I'll leave it like that."
The two officers have been charged with murder and attempted murder over the shooting.
Mr Few's stepfather, Morris German, said that Jeremy was a delightful child who "loved everything, everybody", the AP news agency reported.
Mr German said the boy, who had been diagnosed with autism, had no siblings.
The incident occurred weeks after Los Angeles City Council introduced tougher laws on the use of personal drones.
One of the eye witnesses to the accident was a producer for ABC News.
"All of the sudden [I saw] a flash - like a boom," said Chris Gordon.
"And then sparks and you could see the drone dropping to the ground.
"It landed right over here in the middle of the intersection and cars were actually driving around the drone and it was smoking in the middle of the street."
No one was injured, but the event highlights the risks posed by the increasing popularity of such remote controlled aircraft.
Other recent problems have included a drone crashing into seats during a tennis match at the US Open in New York and a Californian fire department having to temporarily ground helicopters it wanted to use to fight a wildfire because people were using video camera-equipped drones to film the blaze.
Image copyrightGetty ImagesImage captionA teacher was arrested last month for crashing a drone into empty seats at the US Open
Drone shooter
On 14 October, LA City Council voted to make it a misdemeanour to violate new drone-related laws that forbid the flight of an aircraft within 25ft (7.6m) of another person or closer than five miles (8km) to an airport.
But elsewhere in the US, some people have taken the matter into their own hands.
In one case a Kentucky man shot down a neighbour's drone that he said had flown over his property.
Earlier this week, a judge dismissed charges against William Meredith of first degree criminal mischief and first degree wanton endangerment.
Two Britons who died when a whale-watching boat sank off the coast of western Canada have been named as a father and son from Swindon.
David Thomas, 50, and his son Stephen, 17, were among five Britons who died. An Australian man is still missing.
Stephen's mother Julie was among those rescued from Leviathan II.
Officials have said more of the 27 people on board the boat could have died had it not been for the "amazing response" from locals around Tofino.
Canadian government investigators are at the scene near Vancouver Island to examine the wreckage of the vessel, its maintenance history and consider the weather at the time.
The cause of the accident remains unknown but sea conditions at the time of the incident were said to be calm.
'Shocked and saddened'
The Down's Syndrome Association described Stephen as "a very talented young man and a gifted photographer".
Chief executive Carol Boys said: "We were all delighted when Stephen's beautiful image 'Moraine Lake' won the national 'My Perspective' photographic competition last year."
She added: "Stephen's father, David, was a huge supporter of the Down's Syndrome Association and one of the driving forces behind the Swindon Down's Syndrome Group where he was a trustee."
Mr Thomas worked for Microsoft. A statement from the company said they were "shocked and saddened" to hear the news.
Michel Van der Bel, Microsoft UK general manager, said: "Our thoughts and deepest sympathies are with their family, friends and David's colleagues and we will be doing everything we can to support them."
Corene Inouye, director of operations at Jamie's Whaling Station and Adventure Centre, the company that owns the boat, said: "It appears the incident happened so quickly that the crew didn't have an opportunity to send out a Mayday."
She added the skipper of the ship has more than 20 years' whale-watching experience and had completed 18 years with the company.
Company owner Jamie Bray said passengers on the boat were not required to wear life jackets as it has enclosed compartments, which would be difficult to exit in the event of a sinking.
Media captionMarine investigator: "It is much too early to say what the causes and contributing factors of this accident might be"
'Amazing response'
Greg Louie, chief councillor of the Ahousaht First Nation Elected Council, told the BBC's Radio 4 Today programme that "possibly everyone" could have drowned or died of hypothermia had the local community not responded to the accident so quickly.
The incident could have been "a lot worse", Lt Cmdr Desmond James of the Canadian Joint Rescue Co-ordination Centre in British Columbia said.
He added that 21 people would not have been rescued were it not for the "amazing response" by locals.
Image copyrightReuters
The British victims included another male tourist and two British nationals who lived in Canada - one woman from British Columbia and a man from Ontario, according to the British Columbia coroner's office.
Australian Associated Press reported the missing 27-year-old Sydney man was on the boat with his girlfriend and her family when it sank.
His girlfriend's father was among the five Britons confirmed dead, the news agency said.
British Foreign Secretary Philip Hammond said his thoughts were with the family and friends of those affected by Sunday's incident.
Canadian prime minister-designate Justin Trudeau said he was "shocked and saddened" by the deaths.
Whale watching off British Columbia
Tofino is a popular surfing and whale-watching resort near the Clayoquot area
Whale-watching season in Tofino begins in March and ends in late October
The area's rugged coastline and national parks attract tens of thousands of tourists every year
Canada has over 200,000km (124,000 miles) of coastline, meaning it is one of the best locations for whale watching
Image copyrightAlbert Titian/FacebookImage captionBoats from a nearby First Nation community were the first to reach the Leviathan II
A whale-watching boat has sunk off the coast of British Columbia in western Canada, leaving at least five people dead.
The boat carrying 27 people sank near Tofino on Vancouver Island, the coastguard said. Sea conditions at the time were reported to be calm.
Emergency officials said 21 people had been rescued and one other person was still missing.
The nationalities of the victims are not yet known.
Melissa Kai, of the Joint Rescue Co-ordination Center in Victoria, British Columbia said the search-and-rescue efforts had "concluded", and the case of the missing person has been turned over to Royal Canadian Mounted Police.
The boat, Leviathan II, made a mayday call late on Sunday afternoon before sinking about 8 miles (12km) west of Tofino.
Within 30 minutes, a rescue helicopter and boat were on the scene. Other boats in the area were already attending the scene.
Media captionAmateur video shows the stricken whale-watching boat in the sea
The first rescue boats to arrive belonged to the nearby Ahousaht First Nation community, aboriginal councillor Tom Campbell said.
He said he saw the first survivors brought ashore.
"Their looks tell the whole story,'' he told the Associated Press (AP) news agency. "You can't describe looks on people that are lost. They look totally lost - shocked and lost.''
Valerie Wilson, of the Vancouver Island Health Authority, told the AP that the survivors had been admitted to Tofino General Hospital, and three of them had since been transferred elsewhere.
Canadian broadcaster CBC said the boat appeared to have sunk some distance from the shore.
The 20m (65ft) boat was operated by Jamie's Whaling Station and Adventure Centres.
Whale watching off British Columbia
Tofino is a popular surfing and whale watching resort near the Clayoquot area
Whale watching season in Tofino begins in March and ends in late October
The area's rugged coastline and national parks attract tens of thousands of tourists every year
Canada has over 200,000km (124,000 miles) of coastline, meaning it is one of the best locations for whale watching
The last whale watching accident in Tofino happened in 1998, when two people were killed
In a statement on the company's website, owner Jamie Bray said: "It has been a tragic day. Our entire team is heartbroken over this incident.
Media captionThe BBC's Peter Bowes says the situation remains unpredictable
"We are doing everything we can to assist our passengers and staff through this difficult time. We are co-operating with investigators to determine exactly what happened."
Tofino is a popular destination for tourists wanting to spot humpback and Pacific Gray whales, and trips usually last up to three hours.
AP
Reuters
