Humberto Vidal explosion: Thirty-three people die when a Humberto Vidal shoe shop explodes.

The Humberto Vidal explosion (sometimes also referred to as the Río Piedras explosion) was a gas explosion that occurred on November 21, 1996 at the Humberto Vidal shoe store in Río Piedras, Puerto Rico. The explosion killed 33 and wounded 69 others when the building collapsed. It is one of the deadliest disasters to have occurred on the island.