The controlled explosions were at the Rainbow of Hope energy plant, which was abandoned in August after a blast critically injured two workers.
The cause of the blast was never discovered, which was why authorities believed it would be best to detonate the tanks, which had been damaged by fire.
Authorities made their first attempt at destroying the canisters at about 7:30 a.m., but the explosion was not strong enough to breach the main tank, so a second attempt was made. This time, it was successful.
LAPD Commander Andrew Smith said the first explosion attempt had been delayed at first after authorities found a couple more cylinders in a nearby building.
"We wanted to make sure those were safe. We've checked those out, and they are safe," he said.
Smith said the other reason for the delay was authorities wanted to do a last check of the area with their helicopter to make sure no one was in the vicinity of the explosion.
The Foothill (210) Freeway was shut down briefly from Maclay Street to the Ronald Reagan (118) Freeway.
The controlled explosion did not damage any surrounding buildings, and no one was injured.
The Environmental Protection Agency is conducting a criminal investigation into the company, which had sought to extract hydrogen from water to use as fuel.
The EPA said there are no further environmental hazards from the three tanks.
