Based on all the relevant facts and analyses of the classified information, the JIG and MCITF reached the following conclusion: ROKS Cheonan was sunk due to an underwater explosion caused by an attack of a CHT-02D torpedo manufactured and used by North Korea. The evidence points overwhelmingly to the conclusion that the torpedo was fired by a North Korean submarine. There is no other plausible explanation. ---Excerpt from Summary

The damage conditions that would be present in case of a grounding such as longitudinal cutting effects, hull scratch, sonar dome and propeller damage (located under hull bottom), and others were not present. In addition, it is confirmed that there are no known reefs in the incident sea area. Furthermore, since dishing effect (normally generated from underwater explosion) was apparent on the bottom shell plating, the possibility of damage from reefs or other grounding events was rejected.---Excerpt from Analysis on Possible Causes of the Sinking

The ROK ADD, UK, and US investigation teams made the assessment that the explosive was precisely guided to the center of the ship where it exploded in the proximity of below the gas turbine room 3m to the portside from the center, where the shockwave and bubble effect generated by the explosion caused the separation of the ship.
Therefore, there is a high possibility of a torpedo attack. An acoustic guided torpedo which can be launched from a submarine is assessed to be the likely weapon system used.---Excerpt from Analysis on Possible Causes of the Sinking

Analyzing the collected items revealed that ROKS Cheonan was hit and sunk by an underwater weapon carrying mixed explosive composed of HMX (527.91ng in 28 items), RDX (70.59ng in 6 items), and TNT (11.7ng in 2 items) ---Excerpt from Evidence Analysis

Results of the survivors' and sentries' testimony analysis revealed the following: many crew members had floated into the air before falling; two crew members heard the explosion sound twice; no one saw flames, fire or water columns, and no one suffered burn wounds; some personnel suffered from fractures and bruises; many of the survivors believed that a torpedo caused the incident; furthermore, sentries testified they heard the noise and witnessed the flash of light. Considering all the observations above, these are consistent with the UNDEX bubble effect phenomenon. ---Excerpt from Testimony Analysis

Ships of Navy Search and Rescue Group and of KORDI identified 30 objects underwater in total in the vicinity of ROKS Cheonan's sinking site. Most of the objects were confirmed to be debris of ROKS Cheonan, bedrock, and abandoned fishing net which could not have affected the sinking of ROKS Cheonan. ---Excerpt from Analysis on Sea Area of the Incident -

The facts that the evidence, the propulsion device of torpedo, matches in size and shape with the blueprint of North Korean CHT-02D torpedo with Korean alphabet ('1번‘: No.1) marked on it, and that the inventory inspection on ROKN underwater weapons resulted with no missing assets, indicate that the propulsion device of torpedo collected near the origin of explosion is the remains of CHT-02D torpedo manufactured in North Korea. This confirms the assessment that ROKS Cheonan was sunk by the explosion of a North Korean CHT-02D torpedo. ---Excerpt from Propulsion Motor System of Torpedo -

ROKS Cheonan was split and sunk due to shockwave and bubble effect generated by the underwater explosion of a torpedo. The detonation location was 3m to port from the center of the gas turbine room and at a depth of 6~9m. The weapon system used was a CHT-02D torpedo with approximately 250kg of explosives manufactured and used by North Korea.

▶First report in the world on an investigation in which the hull of a ship sunk by a torpedo attack was salvaged<br/><br/>▶Internationally verified report: 73 experts from 4 different nations, 12 domestic civilian institutions, and military personnel actively participated in investigations on various fields and in writing of the report, with every participant and expert supporting the content.<br/><br/>Joint Investigation Group Report on the Attack Against ROKS Cheonan is an investigation report detailing the entire process and results of the investigation carried out by the Civilian-Military Joint Investigation Group.<br/><br/>The report contains 289 pages in the Korean version and 313 pages in the English version. It consists of the overview, the analysis on possible causes of the sinking, the detailed analysis results by team, the conclusion, and the appendix.<br/><br/>The content of the report is comprised of the following:<br/>- Overview includes Situation Overview, Situation Development, and Investigation Activities<br/><br/>- Analysis on Possible Causes of the Sinking contains investigation and analysis on all possible causes which could have caused the sinking, including Non-explosion, Internal Explosion, and External Explosion<br/>- Detailed Analysis Results by Team includes Shape and Trace Analysis, Evidence Analysis, Testimony Analysis, Results of Postmortem and Surviving Patient Examinations, Explosion Type Analysis, Analysis on Shock Response to Underwater Explosion, Analysis on Sea Area of the Incident, and details regarding the collection and analysis of the Propulsion Motor System of Torpedo<br/><br/>- Conclusion includes content on the cause of the sinking and the identification of the perpetrator<br/><br/>- Appendix contains CCTV Recovery and Analysis Result, Underwater Explosion Phenomenon, Analysis Result on Direction and Location of the Explosion, Analysis Result on Charge Size and Depth, Analysis Result on Adhered Materials, Stability Analysis Result, and Basic Hull Strength Analysis Result.<br/><br/>2. Significance of Publishing the Report<br/>The objective of publishing Joint Investigation Group Report on the Attack Against ROKS Cheonan is to: ①Permanently preserve the investigation content as historical data, ②Inform our citizens and every country of the substantial truth, and ③Provide research material to academic groups and research institutions.<br/><br/>Also, this report is significant in the following senses: ①it is the first report on an investigation in which not only the hull of a ship sunk by a torpedo attack was salvaged, and the propulsion device of the torpedo - the conclusive evidence - was recovered, but the explosives' residue was also discovered and analyzed ②it let North Korea and the international community know that even the most covert attack leaves evidence ③it especially sends a solemn warning to North Korea not to engage in any further military provocations.