Police are investigating a Streamwood firework explosion last week that injured four people.
Police said a firework blew up July 28 after it was thrown into a portable bonfire set up in a backyard in the 700 block of West Streamwood Boulevard.
Arlington Heights resident Dan Jacob, 29, said he was at that home that evening with eight or nine other people to watch fireworks at Streamwood's annual Summer Celebration. The fireworks were set off just beyond the backyard.
After the fireworks went off around 9:30 p.m., one of Jacob's friends found a round object in the backyard and threw it in to the bonfire, thinking it was an old baseball, Jacob said.
The object was actually an unlit firework, and within seconds, it blew up.
"We tried to scatter and get away," Jacob said.
Police couldn't provide details on injuries but said none were life-threatening.
Jacob said he and a friend were sent to the burn center at Loyola University Medical Center in Maywood that night. He has treated and released for second-degree burns on his arm and face. Another person had burns and a piece of wood in his inner thigh, Jacob said.
Jacob said almost everyone sitting around the bonfire has complained of ringing in their ears. One friend, he added, is seeing a hearing specialist and might have permanently lost 15 percent of his hearing.
The fireworks have been set off from the same area since 2007, said City Manager Gary O'Rourke. He added that the city puts up an orange fence to block off the fireworks site.
Jacob said his group, along with a dozen others from nearby homes, were sitting behind the fence.
"I've seen the fireworks before and I think we were closer than we should've been," he said. "I'm actually surprised nobody got hit by a falling shell."
Jacob said he was told that police and fire officials found three other unlit shells in the area surrounding his friend's backyard. Police couldn't confirm this.
O'Rourke declined to comment on what the city would do if police find the shell came from the company that set off the festival's fireworks.