CHICAGO (CBS) — Ahead of the Memorial Day weekend, the U.S. Coast Guard and others were warning boaters along Lake Michigan and elsewhere about a hidden danger in the water.

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WBBM Newsradio’s Nancy Harty reports five people died in water electrocution deaths in the U.S. over the Independence Day weekend two years ago, because of electric currents leaking from boats.

Kevin Ritz’s 8-year-old son, Lucas, was killed instantly by 118 volts as he tried to climb aboard a dock in Portland, Oregon, in 1999.

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“Here we are, doing our best, just to get awareness out there – trying to alert people – because I can tell you personally that if we had known about this, had we heard of this before, it wouldn’t have happened to us,” he said.

Ritz was at the Columbia Yacht Club on Wednesday to help conduct a training class for first responders.

A representative for the Coast Guard said boat owners should take responsibility and make sure their water craft don’t have any ground faults in their electrical systems.

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The Coast Guard offers free vessel safety checks. Click here to sign up.