The IDF announced the death of 21 reservists fighting in the Gaza Strip on Tuesday.
Hamas forces fired a rocket-propelled grenade on multiple adjacent structures, along with landmines that the IDF forces had collected and brought into the buildings, which caused a total collapse that killed 19 soldiers and injured several others on Monday.
The incident occurred around 4:00 p.m. in al-Muasi in central Gaza.
In addition, a separate rocket-propelled grenade was fired on an IDF tank which killed two IDF soldiers and injured two others.
Details of the massive explosion are being investigated
It was unclear if the soldiers had violated procedures by bringing the landmines into the structures with them and also unclear how much the collapse of the building was caused by the RPG versus the secondary landmines explosions.
The IDF forces who were harmed were mostly reservists assigned to clear certain areas of dangerous items, such as mines.
Rescue activities went on for hours with the brigade commander having been on site from the start of the incident.
It was unclear what happened to the Hamas attackers.
Names of the soldiers killed
The IDF released the names of 10 soldiers of the 21 that were killed.
Maj.-Gen. (res.) Matan Lazar, 32, from Haifa, a soldier from the IDF's 6261 Battalion, 261's Brigade.
Maj.-Gen. (res.) Hadar Kapeluk, 23, from Moshav Mevo Beitar, and was a Class Commander in the IDF's 8208 Battalion, 261st Brigade.
Sgt.-Maj. (res.) Sergey Gontmaher, 37, from Ramat Gan, who was a soldier in the IDF's 8208 Battalion, 261st Brigade.
Maj. (res.) Elkana Yehuda Sfez, 25, from Kiryat Arba, was a soldier in the 8208 Battalion, 261st Brigade.
St.-Sgt. (res.) Yoval Lopez, 27, from the settlement Alon Shvut in the West Bank, a soldier in the 9206 Battalion, 205th Brigade.
Maj. (res.) Yoav Levi, 29, from the city Yehud-Monoson in central Israel, who was a soldier in Battalion 8208, 261st Brigade.
Maj. (res.) Nicholas Berger, 22, from Jerusalem, who was a soldier in the 8208 Battalion, 261st Brigade.
Maj. (res.) Cydrick Garin, 23, from Tel Aviv-Yafo, who was a soldier in the 8208 Battalion, 261st Brigade.
St.-Sgt. (res.) Rafael Elias Mosheyoff, 33, from the town Pardes Hanna-Karkur near Haifa, was a soldier in the 6261 Battalion, 261st Brigade.
St.-Sgt. (res.) Barak Haim Ben Valid, 33, from Rishon Lezion, class commander in Battalion 6261, Brigade 261.
Names of additional dead soldiers are expected to be announced once the IDF has been able to fully verify their identities and contact their relevant families.
Israeli officials' comments
Israeli President Isaac Herzog wrote that "behind every name whose world has fallen apart - a family that we take to our hearts with sorrow and pain, and at the same time with pride - for the heroism of the generation."
Defense Minister Gallant stated, "On this difficult and painful morning, the enemy's message reaches many homes in Israel; our hearts are with the dear families in their most difficult time. This is a war that will determine the future of Israel for decades to come - the fall of the fighters is a requirement to achieve the goals of the war.
"I send my condolences from the bottom of my heart to the families of the victims of the campaign and best wishes for a speedy recovery to the wounded."
Finance Minister Bezalel Smotrich described the incident as "heartbreaking news. Condolences from the bottom of my heart to the families of the heroes, the entire nation of Israel embraces you with a broken and aching heart. Our commitment is to ensure that the fall of our soldiers will not be in vain."
Knesset Speaker Amir Ohana said, "It's a difficult morning for the people of Israel to wake up to this heartbreaking news. On behalf of the Knesset, I would like to send my heartfelt condolences to the families of the fallen. Each of them is a world full of families, hopes, and dreams that were cut short prematurely. We all wish and pray for a speedy recovery of the wounded."
Yesh Atid Leader Yair Lapid said that he "sends a hug to the families of the soldiers. The entire nation of Israel is with you in your difficult time. May their memory be a blessing."
Agriculture Minister and security cabinet member Avi Dichter said, "Most of the soldiers were reservists, who left entire families without a father and an entire country shocked and in pain."