An explosion at a Shanghai factory owned by a subsidiary of Apple manufacturing partner Pegatron has left 61 workers injured and may threaten to constrain iPad 2 supplies for next quarter. Reuters reports that the blast, which occurred at a factory belonging to Riteng Computer Accessory Co., did not cause a fire, but did injure many, with 23 of the injured requiring hospitalization. According to the report, the plant had not started operations yet, but was expected to produce back panel parts for the iPad 2, and if the safety concerns can’t be overcome quickly, Apple’s supply chain for next quarter could be affected. “Our hearts go out to the people who were hurt in Songjiang,” said Apple spokeswoman Carolyn Wu. “We are working closely with Pegatron to understand the cause of this accident”.