Why did the ABF Singapore Bond index ETF fall 4.48% today 13 Mar 2020?

With this point in mind, it's not only the bond market in SG. Overseas bond & gold market are tanking as well with the stock market. Which brings me to question

1) Where are all the smart money heading to ? (Usually to bond/gold but does not seems like the case now)

2) Funds and companies having a liquidity crunch ? ​​​

Most likely answer i guess is that market is irrational.

the fund holds 80% in SG gov bonds. AAA rated. chance of bond defaulting is highly unlikely. so i would just sit back and continue to collect my dividends and let my RSP take its own course.

or another reason could be a lot are cashing out on this bond fund to buy other undervalued stocks.