Met Police assistant commissioner Neil Basu said: "This is shocking and tragic news".
Police say the nerve agent that sickened Rowley and Sturgess was the same type that nearly killed the Skripals, but scientists haven't been able to tell whether it was from the same batch.
Russian Federation has reportedly denied involvement in both incidents.
She offered her condolences to the relatives and loved ones of Sturgess, 44, who had three children.
But, they say, "it is important that the investigation is led by the evidence available and the facts alone". Sturgess was taken to hospital around 10.15am and Rowley several hours later, around 3.30pm.
Mr Rowley remains critically ill in hospital.
"The Government is committed to providing full support to the local community as it deals with this tragedy", she wrote in a second tweet.
On Twitter, Prime Minister Theresa May said she was "appalled and shocked" by Sturgess' death.
She said: "The staff here at Salisbury District Hospital worked tirelessly to save Dawn".
The Skripals were released from hospital but the investigation into the attack on them continues.
FILE PHOTO: A police officer stands in front of screening erected behind John Baker House, after it was confirmed that two people had been poisoned with the nerve-agent Novichok, in Amesbury, Britain, July 5, 2018.
Britain's public health authority acknowledged on Friday the concerns of people living in the area after the two incidents involving Novichok, but said it was confident that the risk to the public remained low.
Sergei Skripal and his daughter, Yulia, almost died of exposure to Novichok left on the front doorstep of Sergei's home in March.
He makes it look easy, he has so many options, so as he gets older maybe if he loses half a step, it doesn't change how he plays. The third set was one-way traffic as Federer killed the contest with a ferocious forehand after 90 minutes of brilliance.
His first chance came after a poor clearance from Yann Sommer and the ball dropped his way after a Berg shot was blocked. There's no doubt the Swedes will be a tough out for either England or Colombia in the quarterfinals.
Replays showed that Layun did in fact step on Neymar's leg, but his exaggerated reaction after the foul was something to behold. Mexico and Brazil kick off 2018 World Cup soccer games on Monday in the highest profile knockout stage game thus far.
The smartphone is bundled with an inbuilt storage space of 64GB which can further be expanded up to 256GB using a microSD card. While there is no confirmation, the Galaxy Tab S4 might come powered by last-gen Qualcomm Snapdragon 835 octa-core processor.
Even if James is involved in the meetings, he has no interest in hearing elaborate pitches from teams, ESPN reported this week . James flew from the Caribbean island of Anguilla and landed in Van Nuys just after 11 a.m.
The veteran enjoyed a resurgence with the New Orleans Pelicans last season and played some of his best basketball in years. What made James' move to Hollywood surprising is that it seemed to have come without a carefully orchestrated plan.
On the same day, Lionel Messi was sent home in Argentina's loss, the other "GOAT" at this tournament was also eliminated. Portugal haven't reached the World Cup quarter-finals since 2006, when a young Ronaldo led the team to the last four.
Trump has said that he will reveal his pick this Monday, July 9 - 12 days after Kennedy announced his retirement - at 9/8c. Mr Trump had on Friday discussed the nomination with Vice President Mike Pence in Bedminster, New Jersey.
The global community had expected sanctions waivers for some countries, a tactic used in the Obama era to avoid supply shocks. Iran's OPEC governor Hossein Kazempour Ardebili speaks to journalists at a news conference in Tehran, Iran March 7, 2005.
I used to just dribble and stay wide and now I'm in the box more and getting more opportunities". He got it right most of the time last season but we need a bit extra to push for the title".
Belgium's high scorers take on Brazil's miserly defence
The Belgium victor produced a pre-tournament bracket on the entire World Cup knockout stages three days before the opening match. France have always been a footballing stronghold but as we have seen in this World Cup , reputation precedes determination.
Saga Of The Statue Of Liberty Scaler
While on the statue, she lay by the bottom edge of the statue's robe, walked around and sat perched against the national monument. So far, it is unclear whether the woman who climbed the massive statue was involved in the protest, but many are assuming so.
Tropical Depression forms in the Atlantic
This system appears to be less organized, the center said , and the chances for a tropical depression to form are diminishing. During an El Niño, strong upper-level winds roar across the Caribbean and Atlantic, tearing apart developing tropical storms.
Sacha Baron Cohen teases a new Trump-related project
You don't know [expletive]", Trump continues in the clip right before another message appears saying, " Sacha graduates. Trump took to both Twitter and YouTube to lambast Baron Cohen's antics, calling Baron Cohen's stunt "a disgrace".
Thailand cave rescue: Medics reach trapped boys
The governor of Chiang Rai province, Narongsak Osatanakorn, said that all 13 were found safe at about 10:30 pm local time Monday. Other teams are still scouring the mountainside in the hope of finding another way in to the cave. "I want to give him a hug".
Clippers have made trading for Kawhi Leonard a high priority
Spurs teammates questioned the severity of the injury as Leonard's absence continued after the team had cleared him medically. With Leonard adamant about joining the Lakers either now or as a free agent in 2019, the Spurs don't have much leverage.