The number of seafarers who died from asphyxiation in enclosed spaces spiked in 2023, with new data showing most accidents happened during planned work.

More than 30 people died in 2023, the second-highest annual number from records going back nearly three decades, according to ship management association InterManager.

“These numbers appear to be increasing, which is a cause for concern to all involved in maritime safety,” said the group in a submission to the International Maritime Organization.