A stunning video has emerged Friday of commuters in London smashing windows of a subway train to escape after it reportedly filled up with smoke.

"Stuck on the train at Clapham Common and carriages filling with smoke, doors won’t open if it wasn’t for workmen on the platform we wouldn’t have got out!" a witness to the incident wrote on Twitter. 

Video shows people on the platform breaking the windows of a train open so the passengers inside could escape. 

Other subway riders appear to have their bodies wedged in between the train’s doors in an attempt to flee. 

CORONATION OF KING CHARLES OVERSHADOWED BY PRINCE HARRY, PRINCE WILLIAM FEUD

The witness said on Twitter that the "response from station staff was horrific" and Transport for London, which oversees the city’s subway system, should be "ashamed." 

"There are severe delays on the Northern line at present due to an earlier fire alert at Clapham Common station. We are working to get the service back to normal as quickly as possible," Transport for London said in a statement. 

It happened a day before the coronation of King Charles III.

Fox News' Emily Robertson contributed to this report.

This is a developing story. Please check back for updates.