JACKSONVILLE, Fla. – There's a safety alert after police said three men were injured when they were struck by lightning Thursday afternoon while working on the roof of home under construction in Mandarin.
According to the Jacksonville Sheriff's Office report, Melsar Lopez, Gomez Martinez and Salatiel Vasquez and were hit by lightning. Vasquez fell off the roof after he was struck. Workers brought Martinez and Vasquez off the roof while others performed CPR on Lopez until rescue personnel arrived.
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All three were taken to Orange Park Medical Center. On Friday morning, Vasquez remained in critical condition. Lopez and Martinez were in stable condition.
A fourth man on the roof at the time was not injured.
The construction site was empty when News4Jax stopped by on Friday, but a friend said he was by the three men's side at the hospital.
According to the National Weather Service, four people have died this month from lightning. There have been seven lightning fatalities this year, four of which occurred in Florida -- the lightning strike capital. On average, 10 people die each year in the month of July from lightning.
To learn more about lightning, News4Jax visited the JEA Science Theater at the Museum of Science and History.
READ: Lightning safety information for you and your family
Alec Warren, a science education at MOSH, showed how lightning finds east targets using an electricity-generating machine, which gives off a million volts.
"If you're grounded, you get the shocks. And these are small. But they are essentially the same thing as lightning," Warren said.
He said the roofers were likely hit with a strike that's 50 to 100 million volts -- it can easily be deadly.
"The biggest risk is because you're touching the ground and you're touching the building itself -- a tall object," Warren said. "It's sort of like a lightning rod standing on top of a tall building."
Warren said if you can see lightning, or even hear thunder, it's too close and you need to get to a safe place.
"You're talking about millions and millions of volts of electricity. Just so much power," he said.
Experts like Warren said the best thing you can do during a storm is to go inside, stay away from windows and doors. A car is also a safe place as the metal frame and rubber tires keep the electricity out.
Just remember, “When thunder roars, go indoors."