Hundreds of union members have turned out to a Fremantle memorial service for two offshore rig workers killed last year in the Otway Basin off Victoria.

Gathered at South Fremantle football club, they offered prayers of support and solidarity, with two black coffins at the front of the room a stark reminder of the dangers facing riggers.

The Stena Clyde platform was evacuated after Peter Meddens, 32, and Barry Denholm, 60, were killed by “machinery failure” while drilling for gas for Origin Energy.

“It is important we remember their sacrifice in this industry,” maritime union organiser Matthew Elliott told the packed meeting.

“It is equally as important we learn from the tragedy and resolve it should never happen again.”

The workers’ deaths are still under investigation a year later.

Flying Angels Club chaplain Dennis Claughton blessed wreaths laid by union representatives including UnionsWA secretary Meredith Hammat.

“Someone will be held liable,” she told the gathering.

“They have a lot to answer for. Any death is one too many. We will continue the struggle to ensure our workplaces are safe places.”