Federal authorities have announced the discovery of a sophisticated drug-smuggling tunnel running under the U.S.-Mexico border, and charged four people in connection with what prosecutors call a significant blow to a Mexican cartel.

The tunnel stretched about 1,933 feet, sat roughly 55 feet underground and stood about 4.5 feet high, according to authorities. It was outfitted with lighting, ventilation and a rail system to move cargo, and surfaced beneath the floor of a storage room inside a warehouse posing as a discount store near the Otay Mesa Port of Entry.

Investigators said the tunnel was uncovered during a monthslong investigation. More than a ton of cocaine — valued at about $45 million — was seized from three vehicles tied to the operation, officials said. Prosecutors linked the network to the Jalisco New Generation Cartel. The Justice Department charged four men with conspiracy counts including using a cross-border tunnel and importing and distributing controlled substances. The defendants have not been convicted.

Authorities said it is among roughly 99 cross-border tunnels discovered in the San Diego area since 1993. By law, the U.S. side will be filled with concrete.