In what is being called one of the largest methamphetamine busts in U.S. history, authorities seized 750 pounds of the drug estimated to be worth $34 million from a San Jose apartment.

“A seizure of this magnitude is extremely rare,” said Special Agent Casey Rettig, a spokeswoman for the Drug Enforcement Administration.

Palo Alto police made the discovery during an investigation of stolen iPads Thursday.

After receiving a tip about the stolen items, Palo Alto police went to The Woods apartment complex in the 4400 block of The Woods Drive in San Jose and noticed a large amount of methamphetamine during an initial search of the residence.

They immediately contacted San Jose police, the Santa Clara County District Attorney’s Office and the DEA.

Armed with a search warrant, authorities uncovered what they believed was a methamphetamine conversion laboratory, in which the drug is converted from powder to an “ice” or crystal form. Ice methamphetamine has an appearance that is often described as that of broken glass or shattered ice and is ingested by smoking.

DEA chemists, suited up in protective gear, processed the drugs at the apartment.

The drugs were then transported in large boxes to DEA labs where they were further analyzed.

Several undisclosed stolen items also were confiscated, and three people, whose names were not released, were arrested on drug violations, Rettig said. “It’s still a very fluid situation, so we’re not releasing more information.”