Work halted on Philadelphia's new Comcast tower as union laborers walked away from the job in a show of solidarity with striking crane workers.
The Philadelphia Inquirer reports hundreds of laborers clogged the streets Friday morning near the corner of 19th and Arch Streets at the start of the work day.
The International Union of Operating Engineers Local 542, which represents crane and elevator operators, went on strike Monday.
The union and the General Building Contractors Association have agreed on core issues like salary but are stuck on the use of oiler apprentices.
The contractors' association says the jobs are outdated; the union says they're needed to properly train workers.
Construction has slowed but is continuing around the city, with workers have to manually carry up materials normally lifted by Local 542 workers.
