At 18:50 in the evening of 26 August 1988, Pacocha was transiting on the surface with the forward torpedo room and bridge hatches as well as the main induction valve open.

Kiowa Maru was equipped with an ice-breaker bow, with a sub-surface protrusion designed to penetrate and break apart what it struck.

Four men died immediately in the collision and sinking: her commanding officer, Capitán de Fragata (Ship Captain) Daniel Nieva Rodríguez, died securing the bridge access hatch; Teniente Segundo (Second Lieutenant) Luis Roca Sara and two enlisted men were trapped in flooded compartments and drowned.

In the sinking submarine, Teniente (First Lieutenant) Roger Cotrina Alvarado secured the watertight forward torpedo room door and attempted to pressurize the compartment.

As the Pacocha began to capsize water rushed into the compartment, washing Lieutenant Cotrina down the ladder, and, fortunately, forcing the hatch door closed shortly afterwards.

At 20:30, the survivors trapped in Pacocha released their messenger buoy and attempted to call aft compartments on the sound-powered telephone.

Meanwhile, 22 survivors mustered in Pacocha's forward torpedo room: four officers, four chiefs, and fourteen junior enlisted personnel.

At the scene, an assortment of vessels were on the surface, including the submarine, Dos de Mayo, a torpedo retriever, a floating crane, and several small craft.

Locating divers during their off-duty hours was hampered by the lack of telephones in many of their homes, but by midnight, eight were at the scene in SCUBA gear.

By 02:00, three volunteers in Pacocha had donned oxygen breathing apparatuses (OBAs) and walked through compartments as far aft as main control.

After two frustrating hours, improved communications with Pacocha were finally established at 02:27, using the signal ejector to pass written notes to the divers.

A new group of divers arrived on scene at about 05:00 after reviewing salvage connections, escape trunk configuration, and other details on La Pedrera.

Shortly after the divers went to work, they recovered the body of Pacocha's commanding officer, Capitán de Fragata Nieva, just inside the deck access door to the sail.

Utilizing the signal ejector, communication was passed that the crew was in good spirits with enough air to last for seventy-eight hours based on calculations of available oxygen and lithium hydroxide.

While inspecting the submarine, the survivors noted a heavy black cloud rising from below the deck in the forward battery compartment.

Teniente Lindley offered various reasons to wait, and if he had to escape, he wanted the divers to provide SCUBA tanks since he had been trained in their use.

At 11:30, divers completed connecting high and low salvage using Mark V diving umbilicals for hoses and the manufactured fittings.

Finally Teniente Gomez, the senior man, ducked under and began his ascent, followed in turn by Chief Monzon and Petty Officer Reyes.

However, within minutes of reaching the surface, they began suffering great pain in their joints, became disoriented and unsteady, experienced shortness of breath, and displayed symptoms of crepitus.

The second group, led by Teniente Augusto Ivan Aranguren Nieri, completed their escape by 12:25 without incident, and were flown by helicopter to the recompression chamber.

The low salvage line was open to atmosphere on the surface, not pressurized, but was connected to the submarine below the level of water in the bilge.

The final three escapees spent between one-half and one hour breathing from the tanks before escaping at 18:05, by which time personnel topside were again becoming apprehensive.

Carlos Grande Rengifo developed such severe decompression sickness (the "bends"), possibly combined with gas embolus, that he died during recompression treatment.

The Peruvian Navy's efforts to salvage Pacocha began on 30 August 1988, immediately after the crew escaped, and continued for eleven months.

Lieutenant Cotrina credited the sequence of events leading to the closing of the forward torpedo room hatch to a miracle coming from the intercession of then Venerable Marija Petković, whom he was praying to while fighting for his and his crewmate's survival.

Two commissions, one conducted by the Peruvian military, the other by the Vatican came to the conclusion that with the water pressure, it would have been technically impossible for anyone to close the hatch.

On 6 June 2003, Pope John Paul II celebrated Marija's beatification Mass in the Croatian port city of Dubrovnik.