A city inspector interrupted workers who were installing a new cell phone tower without a permit April 24 atop the same Alki apartment building where two other cellular phone companies applied to expand their own communications equipment.

Workers for the wireless broadband company Clearwire were able to install some rooftop equipment before neighbors alerted the Seattle Department of Planning and Development.

"It appeared that an antenna was put up," said Alan Justad, department spokesman. "We issued a notice of violation to remove it."

An inspector posted a fluorescent orange stop-work order next to an outdoor staircase at the Sound Crest Apartments next to Bar-S Playfield. The order threatens a fine and imprisonment if the tower work is continued or disturbed without approval of the department director.

A work crew removed the unpermitted cell-phone antenna last Friday.

Clearwire applied to the city last summer for permission to install three antennas and some microwave equipment on the roof of the apartment building.

In response to questions posed by the Herald, Clearwire spokeswoman Helen Chung stated that, for proprietary reasons, the company doesn't comment on its installation process.