A tznius miracle

A beautiful story heard in a shiur given by Rabbi Avrohom M. Alter that is available online. He said the story in the name of Rebbetzin Kanievsky:

In March, someone packed a car with 100 kilos of explosives and parked it at the CineMall in Haifa. It was parked hear a supporting pillar. Had it exploded, not only would it have destroyed that pillar, but other cars in the lot would have caught fire causing the gas tanks to explode. In that very popular mall, the consequences would have been too horrendously tragic to contemplate.
The explosion did not happen. A passerby spotted some smoke coming from the car and alerted the police whose sappers were able to come and defuse the explosives.
Even Ehud Olmert recognized this was a miracle, although he attributed it to the alertness of civilians.
Here's what really happened:
Several weeks before this event, a girl in Haifa who had been sick and went for tests was told she had stomach cancer. The tumor was so big, and had metastasized, and there was nothing the doctors could do. They told her to go home for her final weeks.
This non-religious girl and her non-religious parents pleaded with the doctors to try. They begged them at least to make an effort. The doctors finally agreed and told her to come back the next day for surgery.
She was assigned a young, inexperienced surgeon. They felt it would be good practice for him, and since there was nothing that could help her, it didn't really matter.
The night before the surgery, this non-religious girl pleaded with Hashem. She said to him, "HaKadosh Boruch Hu, when we had the Bais HaMikdosh people could bring you korbanos to plead their case. Now we have no Kohanim, we have no Bais HaMikdosh. But I still want to bring you a korban."
She went to her closet and took out all her immodest clothing and took it out to the yard and burned them. As the her clothes went up in flames, she cried out, "This is my korban."
The next day this girl went to the hospital in her nightgown. She had burned her entire wardrobe and this was all she had left. She had the surgery. The giant tumor had not metastisized, as was previously believed. It was totally contained. It was easily removed. And it was benign.
She told all her non-religious friends about the miracle. When the girl had recovered enough to get out of bed, her friends brought over all their immodest clothing and made another fire.
Left with nothing to wear, the girls needed new clothes. When that bomb was supposed to explode at the CineMall, these girls were inside buying themselves new, modest clothing.
A miracle that a civilian saw some smoke? Or a reward for tznius?