Very small damage to someone else's property

Question

If someone walks past a parked car with a stroller, the stroller got caught on the plastic casing around the number plate and a small piece broke off, is it wrong to walk off? What would halacha say the owner of the stroller is responsible for?

Answer 1

It would seem from the Shulchan Aruch in Choshen Mishpat סימן שעח - אסור להזיק ממון חברו that one is responsible for all damage caused in the public domain, even unintentionally.

א: אָסוּר לְהַזִּיק מָמוֹן חֲבֵרוֹ. וְאִם הִזִּיקוֹ, אַף עַל פִּי שֶׁאֵינוֹ נֶהֱנֶה, חַיָּב לְשַׁלֵּם נֶזֶק שָׁלֵם,‏
בֵּין שֶׁהָיָה שׁוֹגֵג בֵּין שֶׁהָיָה אָנוּס. ‏
וְדַוְקָא שֶׁאֵינוֹ אָנוּס גָּמוּר, כְּמוֹ שֶׁיִּתְבָּאֵר.‏
כֵּיצַד, נָפַל מֵהַגַּג וְשָׁבַר אֶת הַכְּלִי, אוֹ שֶׁנִּתְקַל כְּשֶׁהוּא מְהַלֵּךְ וְנָפַל עַל הַכְּלִי וּשְׁבָרוֹ, חַיָּב נֶזֶק שָׁלֵם.‏

Which translates to (roughly):
It's forbidden to damage other people's property. If one damaged other's property - even if one gained nothing in the process - one has to pay full damages.
This applies whether one damaged by accident or on purpose.

The exception being if it was entirely out of one's control, as explained later.
^{E.g. falling off a solid ladder, caused by a rung being worm-eaten, or any other Force Majeure as described in ג later: הָיָה עוֹלֶה בְּסֻלָּם וְנִשְׁמְטָה שְׁלִיבָה מִתַּחְתָּיו וְנָפַל וְהִזִּיק, אִם לֹא הָיְתָה מְהֻדֶּקֶת וַחֲזָקָה, חַיָּב. וְאִם הָיְתָה חֲזָקָה וּמְהֻדֶּקֶת וְנִשְׁמְטָה אוֹ שֶׁהִתְלִיעָה, הֲרֵי זֶה פָּטוּר, שֶׁזּוֹ מַכָּה בִּידֵי שָׁמַיִם הִיא. וְכֵן כָּל כַּיּוֹצֵא בָּזֶה. ‏}

E.g.: If you fell off a roof and broke somebody's utensils, or you tripped while walking and fell on a utensil and broke it, in both cases you are responsible for full damages.

Practically speaking one should probably put a note on the car's windshield with contact information.