A woman who lives nearby called 911.
"We heard the truck stop and we heard screaming, so we stood up and saw a small child in the bike seat, the plastic bike seat under the rear tire of the truck," said Loretta Malone.
Police say the truck struck a 3-year girl about 8:15 a.m. on Leland near Winthrop. She was on the back of a bike, ridden by a woman thought to be her mother. Chicago police say the woman lost control of her bike, hit the truck's cab, then the bike fell to the ground and the semi struck the child.
"You saw a bike under a semi-truck, and you just saw a woman in inconsolable agony," said Wes Griffiths, who heard the screams and rushed to the scene.
The 3-year-old was identified as Elizabeth Grace Shambrook, according to the medical examiner.
People at the scene and within the biking community say you should not blame the bicyclist for this tragedy.
"How many is enough for the city to take this seriously? We have been begging and demanding safe infrastructure from the city and we get dashed lines. Dashed lines don't save lives, concrete barriers, protected bike lanes save lives. And now we have a dead toddler," said Kyle Lucas, co-founder of the grassroots infrastructure group, Better Streets Chicago.
Neighbors say they've pushed for speed bumps and other protections along this stretch of Leland east of Broadway.
"For the past couple of years, our community has been begging for help. This is not a through street. This is not a highway. This is a small tree lined street in front of a daycare," said Griffiths.
Another factor investigators were studying was a ComEd truck parked near the intersection, partially in the bike lane.
"I can't imagine trying to navigate between that ComEd truck and a moving semi," said Malone.
In a statement, ComEd wrote, "Earlier today, a non-ComEd vehicle and cyclist collided near a parked ComEd vehicle. We are working with local authorities to understand the circumstances of this tragic accident. The safety and security of ComEd customers and employees is always our top priority, and our thoughts are with the family of the cyclist."
Meanwhile, the stunned community demands answers plus changes, so it won't happen yet again.