It's the 6th confirmed or suspected death in the US. Health officials there say the person was over 50, with underlying health conditions.
Deaths have also been reported in Illinois, Indiana, Minnesota, California, and Oregon.
The new death comes amid major new efforts to restrict access by teenagers to vaping products.
One effort comes from Bloomberg Philanthropies, which is putting $160 million dollars into banning flavored e-cigarettes, and getting makers to stop promoting them to children.
Former New York City Mayor Michael Bloomberg, founder of the group, says the FDA has failed to protect Americans from a risky product.
"They should not allow a product out there, and the law says they should not allow a product out there until they review it. but i think it's just an example of a company that knows a product is bad, but saleable," says Bloomberg.
"Its infuriating," notes Matthew Myers, president of Campaign for Tobacco-Free Kids, adding, "because Juul and these products were introduced just as we were seeing record low levels of cigarette smoking."
New York Governor Andrew Cuomo also announced today that vape shops in the state will be required post health warnings.
More than 3 and a half million teens - about one in five high schoolers - use e-cigarettes. And 97% use flavored varieties.
Delaware health authorities are investigating three possible cases of vaping-related illnesses.
In Houston, Texas, a teen was hospitalized after passing out using a vape pen.
Student Ariel Scott was a witness.
"The girl had handed it to himn, he hit it, he passed out, and he would not wake up. Like he was not waking up. they tried to get him up, he wasn't waking up," said Scott.
No word yet on the boy's condition today.