DETAILS ABOUT CLEANING UP A CHEMICAL AT TACK IN BRITAIN

1 THE ATTACK

On March 4, 2018, a Russian former spy and his daughter were found unresponsive on a park bench in Salisbury, England. British scientists identified the poison involved as a Novichok, a type of nerve agent developed by the Soviet Union. Britain contends that agents of the Russian military intelligence agency, GRU, flew to London, took a train to Salisbury and applied the Novichok to the door handle of Sergei V. Skripal’s home. Though Skripal appears to have been the target of the attack, five people were sickened by exposure to the chemical, including one who died.

2 THE CLEANUP JOB

A year after the attack, the job of decontaminating Skripal’s former home is finally complete, the British government announced Friday. Hundreds of specialists spent a total of 13,000 hours cleaning up 13 sites in and around Salisbury that had been tainted by the nerve agent.

3 THE CLEANUP CREW

Breathing through respirators and clad in sweltering hazardous materials suits, the decontamination workers combed through each of the sites. Backing them up were contractors and people from multiple local, county and national government agencies.

4 THE HOUSE

The environment department said it had turned over control of the house to Wiltshire Council, the local government for the county that includes Salisbury.

“Work will begin shortly to reconstruct and refurbish the house so it can return to being a home again,” Alistair Cunningham, who is leading the council’s recovery efforts, said in a statement.

5 THE POLITICAL FALLOUT

The announcement that the work was done ended one chapter in a bizarre and lethal story, straight out of a Cold War espionage novel, that has badly strained relations between Russia and the West. The incident led to sanctions against Russia, the expulsion of about 150 Russian government employees from Britain and its allies, and the expulsion from Russia of a similar number of people working for those countries.