WIRRAL will remember the victims of the Thetis submarine tragedy this weekend, 70 years after it sank with the loss of 99 lives.

Tragedy struck just a few hours after the Thetis left Cammell Laird on June 1, 1939, for its sea trials, with 103 people on board – twice the number she was designed to carry.

The vessel took on water after an inner torpedo door was opened, leaving people trapped and oxygen running out.

For three days, the men on board battled the effects of carbon dioxide poisoning and waited to be rescued, just 38 miles from shore. Just four people managed to escape.

Over 200 people are expected to attend a private service marking the anniversary on Sunday at Birkenhead Priory.

Harry McLeish, who worked at Cammell Laird for 45 years and started his working life on the Thetis, will be at Fort Perch Rock, New Brighton, on Saturday at 7pm to re-dedicate its HMS Thetis exhibition after a refurbishment.

At 7.30pm, Derek Arnold, the son of the last man to escape from Thetis, will be giving a free talk on Thetis.

On Sunday, Fort Perch Rock will be open from 10.30am to 6pm and anyone with an invitation to the service at the Priory is welcome to view the exhibition free of charge.

On Monday, June 1, at 7.30pm, Derek Arnold will be repeating his talk.

His father, leading stoker Walter Arnold, died in 1974. He was 27 at the time of the Thetis tragedy.