Autumn Parry / The Bakersfield Californian viAP An explosion knocks down one of the remaining towers at the old Kern Power Plant, Saturday, Aug. 3, 2013 in Bakersfield, Calif.

A spectator lost his leg while watching the implosion of a decommissioned PG&E plant Saturday morning and at least four more people were injured, authorities said.

The 44-year-old man, whose name has yet to be released, was gathered along with about 1,000 other spectators to watch the planned demolition of the Pacific Gas and Electric plant in Bakersfield, Calif., the Associated Press reported.

The man lost one leg and received major injuries to the other after shrapnel from the plant explosion flew across the street and struck his lower body, police said. An officer heard the man screaming for help after several plant structures came down, police told the AP.

The man, "sustained an apparent complete amputation of one leg, and the possible amputation of the second," Bakersfield Police Lt. Scott Tunnicliffe told NBC News affiliate KGET.

In California, authorities investigated what went wrong at the demolition of a decommissioned power plant Saturday. Hundreds had gathered around what was deemed a safe area but proved to be dangerous. NBC's Miguel Almaguer reports.

At least two other people received minor injuries that were treated on the scene, according to Tunnicliffe.

Those injured were part of a crowd gathered in a Lowe’s parking lot to watch the demolition that brought down the four-story plant decommissioned in 1986. Thousands of others lined the Rosedale Highway to watch the explosions, KGET reported.

There was a parameter set up around the plant, according to Tunnicliffe. However, according to KGET, PG&E stressed that no official accommodations were made for the general public to watch the explosions.

PG&E did not immediately respond to requests for comment from NBC News.

Roadways around the scene were reopened on Saturday, Tunnicliffe said.

The Associated Press contributed to this report.