PETERBOROUGH - Employees of New Hampshire Ball Bearings Inc. stayed home Tuesday waiting to hear news of when they would be able to return to work after an explosion Monday that blew out windows on the first floor, caused substantial damage inside the building and sent 14 people to the hospital.Tuesday morning employees trickled in and out of the manufacturing plant on Route 202, retrieving items left in their lockers, including car keys, cellphones and coats, left when the building was evacuated Monday afternoon.The blast occurred on the first floor of the building at 3:37 p.m.Second-floor assembly worker Cheryl Christian of Dublin, whose shift ended at 3:30 p.m., had already left for the day and was traveling down Route 202 in her car when she saw the first emergency vehicles headed to the plant.“One lady thought it might have been a bomb going off. She heard two explosions,” a co-worker told her.“I don't know anybody that might have been injured and it appears it might have been the second shift,” Christian said. She said it could have also been a worker from the first shift who stayed during the shift change to make sure the next shift knew what took place in the previous shift, she said.One of those workers, or leads, is Ted Lawrence, a technical specialist in the grinding department on the second floor, whose shift ends at 4 p.m.“I heard a loud bang and the building was shaking,” Lawrence said. “The evacuation was very quick, and little panicked, but very quick.”Tuesday afternoon, Lawrence met up with co-workers at a bar in Peterborough.He and his co-workers are concerned about being out of work as well as lingering safety issues at the plant.“I am very concerned about that and currently right now I am just with a few co-workers sitting back waiting to hear what happened,” Lawrence said. “We don't know the structure of the building. If it is safe and sound. A lot of uncertainty.”Lawrence added there is also a concern about the long-term impact to the business.NHBB vice president of manufacturing Rich Bardellini said at a press conference outside the plant Tuesday that he couldn't answer questions regarding whether employees forced to stay home from work because of the explosion would be paid.Christian said she has been with the company for many years so she is not concerned about a few days at home.“I've got enough vacation time. I could use that if I had to, but some people don't have that flexibility,” Christian said.Though she hadn't heard, she expects NHBB would pay employees for Tuesday at least.“I would think they would pay for today,” she said.NHBB is good to its employees and offers good benefits, she said.