Apparently startled by what must have been a rather unnerving sound, one Philadelphia resident grabbed her cellphone, went to a window and captured what must have been a equally unnerving sight.

It was a tractor trailer dragging its own roof like a long tail down a city street around 10 p.m. Monday.

Turns out the driver hit the bottom of an overpass at 12th and Callowhill Streets, which effectively peeled the roof and back door right off, police told WPVI-TV.

Now one might assume that after such an accident — to say nothing of what the resulting noise must have sounded like — the driver would have stopped immediately.

Well, not so much in this case.

How did the truck driver react?

Yup, the driver kept right on going, dragging his truck's roof and back door — the length of which totaled about 50 feet — down Philly streets for more than three miles, police told the station.

The driver finally came to a stop at 21st Street and Point Breeze Avenue where the Truck Enforcement Department fined him, WPVI reported. No charges have been filed, the station added.

It's unclear why the driver continued to operate the truck after the accident, the station said, adding that it hasn't been able to contact the driver for an explanation.

Cops also are checking along streets where the truck's odd trek began in case any innocent vehicles were sideswiped or damaged, WPVI said.

Here's the station's report: