WEST READING, Pennsylvania: An explosion occurred at a chocolate factory in Pennsylvania, killing seven people and seeing ten staff members being hospitalized.

Hours after the blast at the R.M. Palmer Co. plant in the borough of West Reading, rescue crews using dogs and imaging equipment had pulled one person from the rubble while continuing the search.

West Reading officials confirmed seven fatalities, and county emergency crews indicated that ten others had been hospitalized.

Chief of Police Wayne Holben said the rescue of one person from the rubble "provides hope that others still may be found."

The blast destroyed one building and damaged a neighboring building, and its cause is still under investigation, he added.

At the site of the explosion, Mayor Samantha Kaag said, "It has pretty much leveled.the building in the front, with the church and the apartments. The explosion was so big that it moved that building four feet forward."

In a statement, R.M. Palmer said that the company was "devastated by the tragic events and focused on supporting our employees and their families."

While visiting the site over the weekend, Governor Josh Shapiro stressed that his office would provide "any and all commonwealth resources needed to support ongoing recovery efforts, in addition to the extensive assets that have already been deployed."

Frank Gonzalez, who was a witness to the explosion, said that his sister, Diana Cedeno, was working at the plant at the time of the blast and is among the missing.

"It is not good. It is just stressful waiting, not knowing," he said, according to the Associated Press.

Another witness, Doug Olexy who heard the blast from his house, said, "It sounded like a bomb went off. I mean, all of our houses shook. I have never heard as loud of an explosion in my life," as quoted by the Associated Press.