WASHINGTON – From lightning to flash floods, conditions during severe weather pose a major threat,and can lead to tragedy.

A round of nasty storms is behind the D.C. region this week, but another is on the way. The initial weather system left at least one person dead.

Joshua Davis, 15, was killed along Rock Creek Trail in Chevy Chase. Police say he was riding his bicycle when a tree toppled over and hit him.

The incident serves as a painful reminder of the dangers that arise when storms strike.

“If there’s severe weather we’d ask that you stay out of the parks,” says Holly Thomas, senior urban forester with Montgomery Parks.

“If you see something approaching, or even the wind increasing, seek shelter,” she says.

Heavy rains mixed with strong winds can quickly weaken otherwise healthy trees, according to Thomas.

“The roots aren’t anchored as well when the soil is water-logged and then they’re more likely to fail when you have wind,” she explains.

Thomas urges everyone to immediately report downed trees, hanging branches or severely leaning trees.