Street, who showed up outside an AT&T store at 3:30 a.m., left shortly after a 22-year-old sporting a mohawk asked him, "How can you sit here with 200 murders in the city already?" The Philadelphia Inquirer reported on its Web site.
Street told the man: "I'm doing my job," the newspaper said.
Street had planned to stay in line for most of the day, waiting for Apple Inc.'s iPhone to go on sale at 6 p.m. When he left at 11:30 a.m., Street said he planned to return to his spot.
The mayor said he wants the new device because he loves trying out the latest technology. Apple's new handheld would allow him to work some of the day outside the office, he said.
"We don't have to be sitting in City Hall to be conducting city business," he said.
Philadelphia recently had its 200th slaying of the year. Its murder rate is up from last year, the deadliest in nearly a decade.