Several people heard a small boom.
"I heard somebody say, 'Call an ambulance, call an ambulance.' I was like, 'You're a doctor.' I was like, 'Let's go,'" Brian Murphy said.
The 24-year-old man, who has not been identified, had trouble breathing when Murphy arrived at his side. He was taken to Illinois Masonic in critical condition with burns to his body and head trauma.
The man was tuck-pointing the building when it appears either he or the steel scaffolding he was on made contact a 12 kilowatt electrical wire. The scaffolding was just inches from ComEd wires.
Seventy homes are without power near the 700-block of Oakdale, just east of Halsted.