In the cases provided for in number 1 of the previous article, the Judge or Court may, with justification, impose the penalty one degree higher, to the extent he deems appropriate, if the act is of notorious gravity, taking into account the singular nature and relevance of the risk created and the normative duty of care infringed, and has caused the death of two or more persons or the death of one and injuries constituting a crime of article 152.1.2 or 3 in the others, and by two degrees if the number of deaths is very high.