(WSBT) One week after tragedy struck Silver Beach in St. Joseph, Michigan, police held their first ever beach safety expo, using a new tool to warn beach-goers about the hidden dangers that can lie beneath the water.

It's been less than a week since Berrien County divers pulled the body of 20-year-old David Lambert from Lake Michigan, a day after he jumped off the South Pier in St. Joseph, and never came back up. Now, police are using the Elkhart man's tragic death to help teach a valuable lesson.

It's the closest thing to paradise you're likely to find in southwest Michigan. Silver Beach is a cool refuge on a hot summer day, where people go to make their worries melt away.

But last week, tranquility turned to tragedy.

As the sun peeked out from behind the clouds Sunday, the warning signs were still up, but the caution tape was down and the water was clear. So Robert Graack and his friends say they didn't think twice about diving in off the pier, and taking a dip.

"It's a good thing to come down and do it when it's a hot day!" he said.

Diving off the pier is not against the law. But Graack says he and his friends are careful.

"When the waves are [big], it's just common sense not to jump!" he added.

That's because, even on a calm day, that dip can quickly turn very dangerous — a fact police say many people don't understand or just choose to ignore.

That's why St. Joseph Police are teaming up with the Berrien County Sheriff's Department Dive Team, the U.S. Coast Guard, the American Red Cross and local EMS crews to show beach-goers why the area around the pier is so dangerous, in a brand new video called "Respect The Power."

"There are obstacles in the water, large rocks. The water level is low, and the water's cold!" says St. Joseph Police Sgt. Rick Smiedendorf. "If it's a red flag day, do not go in the water! You could get in some serious trouble."

And many who watched the video say they got the message loud and clear.

"On the calmest days, there's still current," said 14-year-old Katie Glasgow when asked what she learned. "I didn't think it was that dangerous before."

Still, some remain unconvinced. So police say they'll keep pushing play hoping someone hears their message before it's too late.

"Everybody thinks it's not dangerous," said Benton Harbor resident Bev Gould after watching the video with her son. "They need to see this."

Whirlpool's Hispanic Network was also on hand at Sunday's beach safety expo, holding their own pier safety presentation and handing out Spanish-language safety brochures.

Officers hope to hold another safety expo later this summer.