On January 19, 1917, in the darkest days of World War One, a massive explosion at the Silvertown munitions factory rocked the East End, killing 73 people, injuring 400, destroying 900 homes and sending shockwaves across Essex.

But long before the devastating blast, the cause of which remains a mystery, sparks were already flying at the TNT factory as a group of female workers fought for equal rights and pay. Sparks that still resonate with us today.

A new play, Out of the Cage, opening at Park Theatre this week, is a rare all-female production, which looks at the hours leading up to the disaster and is produced by Lindsay Fraser, who grew up in Kent, studied in Loughton and now lives in Newington Green.

She says: “I couldn’t believe that I had never heard about it and I didn’t know there had been an explosion which wiped out four blocks of the East End and could be heard in Southampton and killed hundreds.

“I couldn’t believe that I hadn’t learned about it at school, having grown up not that far away and having lived so close to it.“ The 27-year-old, who runs theatre company Fine Line, also stars as a young worker, Carrie Sefton, in the two-hour, two act period play, which uses movement and song to capture the spirit of the age.

“She’s in her early 20s and, I think, represents a huge amount of women at that time,“ says Lindsay.

“She wasn’t that political, but she found herself caught up with this group that are looking for a revolution.

“She absolutely believes in equality and that’s what’s driving her, but she has had a pretty tough time growing up and her husband is now in the war, so interestingly she has this struggle between wanting better pay and conditions and enjoying being liberated.

“That was the struggle. It wasn’t all bad as this was the first time that women could work and do men’s work.“ Lindsay, who has previously produced the all-male play Bound, met writer Alex McSweeney when they worked together at Southwark Playhouse on Execution of Justice.

“He sent me the script to read in March last year. I was really surprised he had written it because it’s a wonderful play for woman about women munitions workers in the First World War, and I just didn’t really expect that he would have written a play like that.“ “But it turns out he’s a real feminist and knows a huge amount about that time and the munitions acts.“ The pair were keen to stage the play early in 2015 to coincide with the date of the explosion and the events marking the World War One centenary.

Lindsay, who studied acting at East 15 in Loughton, says the project has made her think about how far equality has come since the Great War but she adds: “There is still a way to go.

“As a young actress so many parts I go up for are the girlfriend or the wife or the victim, and I think it’s quite unusual to find characters that are strong and interesting.“ In contrast Out of the Cage offers the complete opposite and has inspired her to seek out more plays with better parts for women.

“This play is so unusual. It’s just so rare you find a really great play with just women and the parts are very rounded, three- dimensional, flawed and loveable, and that’s quite rare.

“You can tell with the girls in the show how exciting it is to get your teeth into parts like this because they really don’t come along very often.“

Park Theatre, Clifton Terace, Finsbury Park, until February 14. Details: 020 7870 6876, parktheatre.co.uk

See archive footage and photographs of women working in the factories below.