Joan Bartlett and Violet Pengelly - Westferry Road, London, UK - Firefighter Memorials on Waymarking.com

The plaque contains the wording:

In Memory of

Joan Bartlett, aged 18
and
Violet Pengelly, aged 19

Members of the Auxilliary Fire Service

Amongst the first serving firewomen to die on
duty during an air raid
on
September 18th 1940

The London Fire Journal blog tells us:

In 2008, the former Millwall Fire Station was converted into an apartment block named for Violet Pengelly and Joan Bartlett, members of the London Auxiliary Fire Service killed during World War II.

The young pair were among those who lost their lives during a bomb attack at the height of the blitz.

Violet, 19, and Joan, 18, were among the first women to sign up to the Auxiliary Fire Service in 1938, and were based at a sub-station in the Saunders Ness Road School on the Isle of Dogs when World War II broke out a year later.

The two were killed – along with 24 other emergency workers – when the school suffered a direct hit from a high-explosive bomb on the night of September 18, 1940.

The new residences are named Bartlett Mews and Pengelly Apartments.