TWO HARBORS, Minn. — Authorities are investigating the weekend death of a 42-year-old Twin Cities man, who surfaced in distress during a shipwreck dive only to go underwater and later be located unresponsive on the bottom of Lake Superior.

Aaron Timmerman, of New Hope, had been scuba diving with a group on the wreck of the barge Madeira — a popular diving site in the waters off Split Rock Lighthouse State Park. Witnesses saw Timmerman surface and call for help, but no one was able to get to him before he went under, the Lake County sheriff’s office said Monday.

Timmerman was located on the bottom of the lake by two members of his group and brought to the surface. Authorities arrived on shore shortly after 1 p.m. Saturday to find other divers attempting lifesaving efforts.

The cause of death will be determined by a medical examiner, the sheriff’s office said.

Timmerman was pronounced dead at 2:10 p.m. at Gooseberry Falls State Park, where the Two Harbors Fire Department prepared a landing zone for a medical helicopter.

The Madeira was one of 20 vessels damaged or wrecked in November 1905 during the Mataafa Storm, which is generally regarded as the worst in recorded Lake Superior history. The Madeira wreck featured a heroic rescue effort that saved nine members of the 10-person crew.

As a result of the storm, Split Rock Lighthouse was erected in 1910 within sight of the Madeira wreck.

Timmerman’s family has set up a crowd-sourcing webpage to help with funeral costs.