London underground terror incident parsons green station

You're referring to the Parsons Green bombing, which occurred on September 15, 2017, at Parsons Green Underground station in London, England.

Here's a brief summary of the incident:

The Parsons Green bombing was the fifth terrorist attack to occur in the United Kingdom in 2017, and it highlighted the ongoing threat posed by lone-wolf terrorists and the need for continued vigilance and cooperation between law enforcement agencies.