This incident could lead to a wider war on Syria:
Five people were killed and at least eight were wounded Oct. 3 when at least three Syrian shells struck the Akçakale district of eastern Şanlıurfa. One of those killed was a 6-year-old child, according to officials.

Akçakale is a few steps north of the border with Syria. There is a crossing point with the name Tal Abyad that the Free Syrian Army captured on September 19. During the following days’ fighting over the area a petrol station went up in flames which allegedly caused many casualties.
Some 70 kilometer (~40 miles) south of that crossing point lies al-Raqqa around which there have already been clashes and which the insurgents want to destroy next. This even while the people in the city, including opposition supporters, are begging thze insurgents not to liberate them (video report):
More than 500,000 people are estimated to have fled to the northern city of al-Raqqa over the year-and-a-half long conflict in Syria.
That influx of internally displaced Syrians has doubled al-Raqqa’s population.
Now, as opposition fighters say they plan to take the city from the forces of President Bashar al-Assad, civilians are pleading with the fighters to spare them the violence that would ensue.
It is not known who fired the mortars that landed in Turkey. That might have been Syrian Arab Army troops firing on insurgents. But it also might have been the insurgents from the Free Syrian Army that have an interest in getting Turkey to fight for them.
The Turkish prime minister Erdogan is under a lot of pressure for his support of the insurgency in Syria. The Turkish public opinion is by a large margin against this policy.
It is obvious that the insurgencies supply route for their attack on al-Raqqa is through Tal Abyad and the Turkish town of Akçakale. Those five Turkish people killed there today along that supply line are a direct consequence of Erdogan’s material support for the insurgency.
Any further dead in an escalation would be, like the dead today, his direct responsibility.
The Obama administration is just as guilty as Erdogan is. Three bombs the insurgents exploded today in Aleppo killed 34 and injured over 120 people. This only days after Hillary Clinton increased the material support for especially those insurgents in Aleppo. The “non-lethal” radios the U.S. is giving to the insurgents are just as deadly as the bombs those radios trigger.