Within moments of chaos breaking out in London, Conservative MP Tobias Ellwood, whose brother was killed in the Bali terror attack, rushed to the aid of a stabbed police officer.
Mr Ellwood performed mouth-to-mouth resuscitation on the officer, who later died of his injuries.
A mere 10 metres away was the attacker, who was shot dead by police after scaling the security wall and entering the grounds of the Houses of Parliament.
Mr Ellwood, who served in the Royal Green Jackets and reached the rank of Captain, used his first-aid training to try to stem the officer’s bleeding.
Photographs showed the MP with bloodied hands and blood on his face.
Speaking just hours after the attack, which has left five people dead so far, Mr Ellwood described the incident as a “huge tragedy”.
“I am a witness, I was the last one on the scene before he died so I am not allowed to say anything,” he told UK tabloid, The Sun.
“It is now murder, I was on the scene and as soon as I realised what was going on I headed towards it.
“I’m not allowed to say anything, I’ll get into trouble.
“It’s very sad,” he added.
The 50-year-old is no stranger to terrorism — his 39-year-old brother Jonathan was among the 202 people killed in the 2002 Bali nightclub bombings.
Touched by Mr Ellwood’s remarkable story, people have taken to social media to praise his “heroic” actions.