Emergency officials said glass fell from the 48th floor of the Austonian, the Austin, Texas, tallest building Thursday afternoon.

There was no word as to why, but emergency personnel at the scene said no injuries have been reported. Congress Avenue was briefly shut down between Second and Third streets. A nearby parking lot was shut down as well.

Austin police received a 911 call from a person reporting “raining shards of glass,” Austin police said. The glass from the building is designed to shatter when struck, officials at the scene said.

Fire officials said they think a glass pane on an exterior balcony shattered, but they are not certain what caused it to break. Austin Fire Battalion Chief Richard Thompson said no one is living in the unit where the pane fell and there’s no active construction on that floor.

One car in a parking lot below was damaged by falling glass. Building management planned to leave notes on the other cars in the lot to notify owners about the incident.

Crews cleaned up glass that spread out for almost a block on Congress Avenue and covered parts of a parking lot adjacent to the building, near Third Street and Congress.

The Austonian, which some have described as a giant USB stick, is a 56-story condominium tower at Second Street and Congress Avenue, and at 683 feet tall, became the tallest skyscraper in Austin when it opened in 2010.

In October 2011, pieces of glass fell from the downtown high-rise after an unknown object hit an exterior window on the 45th floor, officials said at the time. No injuries were reported.

The object hit the window on the building's east side, Austin Fire officials had said.

Earlier that year in June 2011, the nearby W Austin Hotel & Residences briefly closed after eight panes of glass shattered and fell from balcony railings more than 200 feet above the street. Four people were injured.