A Chicago woman was among the activists aboard the flotilla trying to break Israel's three-year blockade.
The bloody confrontation took place in international waters, which has resulted in outrage from several countries. Despite warnings from Israel to stay away from Gaza, a convoy of six ships set sail from turkey.
Chicago area pro-Palestinian groups are worried about a local activist who was part of the flotilla, and so is the woman's mother.
On one of the ships was Chicagoan Fatima Mohammadi. The state department told her mother in Idaho no Americans were killed.
"Very scared. And of course last night when I heard that they had been attacked I just basically fell apart as any mom would, and I tried to tell her not to go on this because I knew that this was going to be dangerous," Teresa Mohammadi told ABC7 Chicago.
When the deadly incident happened, the scene was chaotic as Israeli naval commandos stormed the six vessel flotilla carrying humanitarian aid and hundreds of pro-Palestinian activists aboard one of the ships was Chicagoan Fatima Mohammadi.
"We are all in a holding pattern with 16 dead. We hope Fatima is not among them," said Kevin Clark, Midwest coordinator, Free Gaza Movement.
While the exact number of dead is still unknown, Clark says there should never have been any deaths. His says his organization and other activists from around the world were just trying to get aid to the blockaded Gaza strip.
"The purpose was to do what the government's of the world are not that getting food, medical supplies into Gaza," said Clark.
But, Israel's consulate general in Chicago believes the real purpose of the flotilla was political, not humanitarian. Orli Gil says Gaza has enough aid.
"Since the last cease fire in 2009, one million tons of humanitarian aid one ton for every man, woman and child in Gaza," said Gil.
Gil says Israel warned the activists several times not to get close to Gaza. She says her country offered to deliver the aid to Gaza or suggested going through Egypt. Gil says Israeli soldiers only used their weapons after they were attacked by the activists.
"Sling shots, bats knives metal bats break heads and so on," said Gil.
The Free Gaza Movement says their activists knew the flotilla would be risky but did not think it would be deadly.
"We are all numb for this to happen," said Clark.
Gil and Israeli's prime minister Benjamin Netanyahu says while they are sorry for the loss of life, they fully back the action of their soldiers. Netanyahu was scheduled to meet with President Obama Tuesday in Washington, but Netanhayu canceled to deal with this situation.
The White House released a carefully worded statement saying, it regretted the loss of life and that it was working to understand the circumstances of the incident.